I recently discovered that Peter Dinklage is a vegan, which means that he neither eats meat nor does he eat any products produced by animals, like milk and honey.
So what does he eat in scenes where you see him biting off a bone?
Peter Dinklage is a vegetarian. He has been a meatless eater since the age of 16.
In all of the scenes that require him to be eating meat with his dear family in King’s Landing, Dinklage eats tofu or fake meats instead.
Source 1 (emphasis mine)
"I wouldn't hurt a cat or a dog – or a chicken or a cow. And I wouldn't ask someone else to hurt them for me. That's why I'm a vegetarian."