Our Thanksgivings were mostly traditional. Now that I've had more exposure to other families, I realize that they were also a lot more abundant and with a greater emphasis on variety. We usually have a relish tray: celery and carrot sticks, pickle spears, black olives (to be put on fingers). If we have guests, it will go out before the main meal with crackers and cheese. We usually offer sherry as a pre-dinner drink. The main was always turkey (I started making a vegetarian alternative for myself later on). We had mashed potatoes, dressing (we never stuffed the turkey in order to maximize drippings), a quart or more of gravy (due to the abundance of gravy), jellied cranberry sauce from a can (I started making it from fresh later on), simply cooked veg of some sort (steamed or glazed carrots, steamed green beans or peas, maybe both), and some kind of sweet potato (mashed or glazed… no marshmallows, ever). Dessert was normally pumpkin pie, though we sometimes also have apple or pecan. Oh, we also had soft rolls.
Christmas usually was the same thing, though dessert was plum pudding with hard sauce, maybe some mince pies if we could find them. Occasionally we'd have ham instead, but that usually went for Easter. Ham was accompanied by scalloped or au gratin potatoes, peas or beans (again, done very simply), rolls, and a green salad.