Query below lists:
(A) all tables and their primary keys constraint (PK) accessible to the current user in Oracle database
(B) all tables and their primary keys constraint (PK) in Oracle database
Query was executed under the Oracle 12c Database version.
Query
A. Tables and their primary keys constraint accessible to the current user
select tab.owner as schema_name,
       tab.table_name,
       acc.constraint_name,
       LISTAGG(acc.column_name,',')
              WITHIN GROUP (order by acc.position) as columns,
       con.status
from sys.all_tables tab
left join sys.all_constraints con
          on con.owner = tab.owner
          and con.table_name = tab.table_name
          and con.constraint_type = 'P'
left join sys.all_cons_columns acc 
          on con.owner = acc.owner
          and con.constraint_name = acc.constraint_name
where tab.owner not in ('ANONYMOUS','CTXSYS','DBSNMP','EXFSYS', 'LBACSYS', 
      'MDSYS', 'MGMT_VIEW','OLAPSYS','OWBSYS','ORDPLUGINS', 'ORDSYS',
      'SI_INFORMTN_SCHEMA','SYS','SYSMAN','SYSTEM', 'TSMSYS','WK_TEST',
      'WKPROXY','WMSYS','XDB','APEX_040000','APEX_040200', 'DIP', 
      'FLOWS_30000','FLOWS_FILES','MDDATA', 'ORACLE_OCM', 'XS$NULL',
      'SPATIAL_CSW_ADMIN_USR', 'SPATIAL_WFS_ADMIN_USR', 'WKSYS', 'PUBLIC',
      'OUTLN', 'APEX_PUBLIC_USER')
group by tab.owner,
         tab.table_name,
         acc.constraint_name,
         con.status
order by tab.owner,
         tab.table_name;
B. If you have privilege on dba_tab_columns and dba_tables
select tab.owner as schema_name,
       tab.table_name,
       acc.constraint_name,
       LISTAGG(acc.column_name,',')
              WITHIN GROUP (order by acc.position) as columns,
       con.status
from sys.dba_tables tab
left join sys.dba_constraints con
          on con.owner = tab.owner
          and con.table_name = tab.table_name
          and con.constraint_type = 'P'
left join sys.dba_cons_columns acc
          on con.owner = acc.owner
          and con.constraint_name = acc.constraint_name
where tab.owner not in ('ANONYMOUS','CTXSYS','DBSNMP','EXFSYS', 'LBACSYS', 
      'MDSYS', 'MGMT_VIEW','OLAPSYS','OWBSYS','ORDPLUGINS', 'ORDSYS',
      'SI_INFORMTN_SCHEMA','SYS','SYSMAN','SYSTEM', 'TSMSYS','WK_TEST',
      'WKPROXY','WMSYS','XDB','APEX_040000','APEX_040200', 'DIP', 
      'FLOWS_30000','FLOWS_FILES','MDDATA', 'ORACLE_OCM', 'XS$NULL',
      'SPATIAL_CSW_ADMIN_USR', 'SPATIAL_WFS_ADMIN_USR', 'WKSYS', 'PUBLIC',
      'OUTLN', 'APEX_PUBLIC_USER')
group by tab.owner,
         tab.table_name,
         acc.constraint_name,
         con.status
order by tab.owner,
         tab.table_name;
Columns
- schema_name - table schema name
- table_name - table name
- constraint_name - table's PK constraint name
- columns - list of table's PK columns separated with ','
- status - table's PK status (ENABLED / DISABLED)
Rows
- One row represents one table in a database
- Scope of rows: all tables and their PK constraint if exist in a database
- Ordered by schema, table_name
Sample results

You could also get this
Get this interactive HTML data dictionary in minutes with Dataedo.

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Bart Gawrych
                                                                        Bart Gawrych
                                 Oracle database
                                                                Oracle database
                                 SQL Server
                                                                                                SQL Server
                                             Azure SQL Database
                                                                                                Azure SQL Database
                                             Snowflake
                                                                                                Snowflake
                                             IBM Db2
                                                                                                IBM Db2
                                             Teradata
                                                                                                Teradata
                                             PostgreSQL
                                                                                                PostgreSQL
                                             MySQL
                                                                                                MySQL
                                             MariaDB
                                                                                                MariaDB