My 16 month old started the same thing a month or two ago. It wasn't anything too serious at first, so we just got him accustomed to us taking his cup in between him eating. Now, he hands it to us, but if we are not quick enough, it still lands on the floor. It's a bit annoying but better than wiping up milk and food from the floor. A couple of weeks ago he threw a fit as he wasn't eating what we were eating and actually threw his food. He immediatey went to his crib for about 10 mins until he had calmed himself down and we gave him his food again. He threw it again and he went back in his crib. By then he was too hungry and understood it wasn't going to get him anywhere but to bed. My sister-in-law has been able to teach her 15 month old to say "all done," so she at least has a head start to run to him before he actually thoughs the bowls or cups. Good luck (we all need it, lol)!!