DROP TABLE removes tables from the database. Only its owner may destroy a table. To empty a table of rows, without destroying the table, use DELETE.
DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is referenced by a view or a foreign-key constraint of another table, CASCADE must be specified. (CASCADE will remove a dependent view entirely, but in the foreign-key case it will only remove the foreign-key constraint, not the other table entirely.)
To destroy two tables, films and distributors:
DROP TABLE films, distributors;