How much ham to feed 100 people?

It would depend on how you are serving it. If you are serving it as a baked or roasted ham, roughly fifty pounds would do (1/2 pound servings), but you might want to purchase a bit more for seconds for bigger eaters. If you are serving it in sandwiches, 25-50 pounds depending on the type of sandwiches and the other elements of the sandwich (cheese, lettuce, tomato, etc.).
It would depend on how you are serving it. If you are serving it as a baked or roasted ham, roughly fifty pounds would do (1/2 pound servings), but you might want to purchase a bit more for seconds for bigger eaters. If you are serving it in sandwiches, 25-50 pounds depending on the type of sandwiches and the other elements of the sandwich (cheese, lettuce, tomato, etc.).