Thanks for the comments everyone! Let me further explain my issue. Dairy sneaks into all sorts of restaurant food. As already mentioned, butter is commonly put on top of steaks after they have been cooked. This is the case in many normal restaurants (outback, ruth's chris) as well as on the cruise (RC Chops, japanese steakhouse, and so on). While that can be easily dealt with, it is the unknown that makes it hard, particularly in the buffets. Chili, omelets (milk mixed into the egg sauce), soups, rolls, salad dressings, curry, hamburgers, and many other all have the potential of having dairy. On the Disney cruise someone was able to point out which foods were safe. On RC, it took a lot of effort to find someone, and then they had to go back and talk to someone else. I could easily spend 30 minutes just finding out if food are safe, and that gets to be tiresome.
RC menus now say "lactose free options available" but I found the waiters to not be very knowledgeable about what that menu. And, as I already said, they have very limited dessert options. I can only eat so much jello or fruit for dessert!