At that age they are seeing the food goes away over the edge. Magically it gets cleaned up.... And, they get attention from you (or from the family pet).
Yes it makes mommy angry, but so what? Does it affect her?
It's funny to see mommy react....it is attention.
I ran a registered daycare out of my home. I loved to be challenged by toddlers....its like a week long puzzle.
One...
Don't let the dog eat it...
Two...
Constructive reaction.
If you react and it has no affect on her....it is not constructive. Taking the food away and giving it back will become a game too. You are teaching her that you will cave in the end. That is a negative reaction.
So, calmly take it away and make her get down ((Teaching her that throwing food means she doesn't want it)). Do not use anger...make sure it is a reaction for her action, not a reaction for your anger.
Calmly make her get down and pick it up....every bit, every time. And throw it in the trash ((Teaching her that the food doesn't disappear, it goes down to the floor when she throws it; food doesn't go on the floor; and it is not appropriate to feed the dog her food)).
No matter how funny her method of cleaning up her mess.....don't let her see you giggle or laugh. Pretend you are not paying attention (but still keep an eye on her). She is not entertaining you, she is being responsible.
Do not congratulate her on a good job when she is done or you may entice her to make messes to clean up. But congratulate her on eating neatly.
Sure, it is a pain in the butt to keep getting her down. But it will teach her responsibility for her action, and teach her the consequence for not listening to mommy's "NO". Your action is essentially speaking her language. It may take a few times for her to understand it. So, you MUST be consistant. Everytime you do these things, you are instilling more and more that her every action has a consequence. The first time you let it go, you are starting all over again.
My toddlers always wiped their eating area when they were done. Of course, I always followed behind to do a better job while they got a video to watch. If it took them too long to clean up because they made a mess, they missed out on the video already playing. They feel a sense of urgency to finish so they can go watch their beloved dinosaur..making them dislike their "Mess". They are less likely to give the caregiver the 'I hate you!' tantrum when your actions are reacting to their initial action and not from your anger.
It takes a long time for some children to realize that the mess they are making is the mess they must clean up. But with consistency, they catch on. At her age, making her immediately clean it up after taking the food away will also be a shortcut to make her realize the mess is her own doing.
I love the feeling of accomplishing a learning experience for a toddler when most adults feel that they are incapable of understanding you. They do learn from every action...sometimes it takes some creativity. She is at the beginning of toddler years...a great time to start constructive reactions that will be the difference between a two year old and a 'terrible two' year old.
Good luck.