To empty a database follow these steps:
1. Go to cPanel >> Databases section >> phpMyAdmin menu.
2. Select the database you wish to empty. A list with all the database tables will appear on the left (you may have just one database if only one website is hosted):
3. Tick Check All to select all tables and choose the Drop option from the With selected drop-down list:
4. This will execute the DROP TABLE SQL query to empty all the tables at once. On the next step, confirm you wish to proceed by clicking the Yes button: