Query to show all table names
select table_name from dba_tables
SELECT *FROM TAB;
Query to see all the objects in sql
This is a very simple query to get all the objects in sql. User_Objects is sql system table which include all object information as a records.
select * from USER_OBJECTS;
This is small query but it could be very helpful for you.
Create the table into the trigger using pl sql
To create table into the trigger using pl/sql you can try following code in SQL query editor or in stored procedure.
Create or replace trigger b_br after delete on EMP
dbms_output.put_line('Table Creation in process..');
execute immediate 'create table b_t(b varchar2(10))';
Delete from EMP;
Same way you can add more columns in tables with different data types.