I don't understand what you mean by "sharing". Are you actually sharing an entree? You will be lucky if they don't charge you for the additional person.
They don't charge you to share entrees at a table service. You just can't share at a buffet though.
DH and I or DD and I did it several times on our last trip and DD and I plan on doing it this trip as well. No issues at all. Between the Appetizer, Entree and Dessert, it's a ton of food.