I used to do Thanksgiving for about 20 and Christmas dinner for about 8, though not any more.
Thanksgiving was turkey (25 lbs), and a small ham (10 lbs) mashed potatoes, stuffing, 2 veggies, candied yams, gravy, rolls. Dessert was at least 3 different pies.
Christmas was ham, mashed potatoes, 2 veggies, candied yams, gravy, rolls. Dessert was at least 3 different pies.
One year at Christmas we had lasagna for 8.
Now its just John and I, and its a small turkey for Thanksgiving and a ham steak for Christmas. However I make a dinner almost every night.