With help of this addon people does not have to leave their Facebook application and can make a reservation just right there. You would need to add a menu in Facebook to your business page and your clients will be able to make a booking form Facebook. For demo open ReDi Restaurant Reservation page in Facebook and click on Reservations menu on the left side or click on this direct link for demo: Facebook Demo Add-on
The information about ohter add-ons you can find on this page.