At Crystal Palace, a buffet, they'll deduct 2 A TS credits and 1 C TS credit for your meal. The <3 will eat for free, off his/her own plate, and will also get a free beverage. This will be the case at any buffet (Boma, Chef Mickey's, etc.) or family style restaurants (Garden Grill, 'Liberty Tree Tavern (dinner), etc.)
At regular, order off the menu TS restaurants, for those same 3 credits you will get 2 A appetizers, 2 A entrees, 2 A desserts, 1 C appetizer, 1 C entree and 1 C dessert, plus 3 beverages. Your <3 is welcome to share off of everyone else's plate. If you want him/her to have his/her own meal and/or beverage, expect to pay OOP for this.
Buffets/family style restaurants really are a great bargain with kids under 3, whether you're on the DDP or not. But you'll also have plenty of food at the other restaurants; the question is, will it be to your baby's liking. If not, it will be less than $10 to order an additional child meal and beverage--still a great deal, IMHO.