Find out How Many Rows in Table in a User

DECLARE
val NUMBER;
BEGIN
FOR I IN (SELECT TABLE_NAME FROM USER_TABLES) LOOP
EXECUTE IMMEDIATE 'SELECT count(*) FROM ' || i.table_name INTO val;
DBMS_OUTPUT.PUT_LINE(i.table_name || ' ==> ' || val );
END LOOP;
END;

Drop All Table in a User

BEGIN
FOR c IN (SELECT table_name FROM ALL_tables where owner='TEST_GPG_GL') LOOP
EXECUTE IMMEDIATE ('DROP TABLE "' || c.table_name || '" CASCADE CONSTRAINTS');
END LOOP;
END;