Number of tables the currect user owns:
select count(1) from user_tables;

The list of owners whose tables curr user has access to:
select owner from all_tables group by owner;

Views of tables:
– dba_tables
– all_tables
– user_tables

– user tables is you
– all tables you have access to including those owned by other users
– dba tables for dba and basically all tables (?)