Just as easy as creating tables and databases is, so too is deleting them.

DELETE TABLE EMPLOYEE;

Or to delete a database

DELETE DATABASE EmployeeDatabase;

And finally, to delete the data within a table, but not the table itself, use the TRUNCATE statement.

TRUNCATE TABLE EMPLOYEE;

Well you are now on your way to creating formative relationships with a myriad of eager databases. While I haven't taught you everything there is to know about SQL (you still need to know functions and a plethora of other things), this should get you started.