When I got my first cat, he didn't do that - but when we got Pfeffa, SHE would paw single pieces of dry food out of her bowl to eat them, and then he must have seen her do this, and thought, "hey, what a great idea!" and then he started doing it too :roll:
It does get rather messy - they'd leave crummies all around the bowl. A shallow lipped tray placed under the bowl can help.