1. select tname from tab;
2. select table_name from user_tables;
3. select table_name from all_tables where owner = 'YOURSCHEMA';
4. select object_name from all_objects where object_type = 'TABLE' and owner = 'YOURSCHEMA';
5. replace "TABLES" with "SEGMENTS" in some queries. For example, "select segment_name from user_segments;" would show you all segments associated with all of your tables, in case a table has more than one segment in the case of LOBs or Partitions.
When connected to SQL*Plus or other SQL interface program, type the command DESC ALL_TABLES to see what columns are available.
If you are connected as YOURSCHEMA then you can replace it in the query with the keyword USER. Just like in SQL you can say SELECT USER FROM DUAL, you could say ...
select table_name from all_tables where owner = (SELECT USER FROM DUAL);
which is the same as saying ...
select table_name from all_tables where owner = USER ;