Hi Ann,
Welcome to the Moms Panel, thank you for your question! This is a very relevant question these days, and I understand how important it is to be as frugal as possible when it comes to vacation expenses.
The standard base gratuity is 18 percent of the bill, which can be a significant expense in the finer restaurants. I am sure you could find plenty of people that would agree that fifteen percent is "good enough", but I think you will find that the service typically warrants at least the eighteen percent. It would be a shame to budget the fifteen percent, only to receive exceptional service and not be able to tip accordingly.
Since you've asked the question, I am guessing that you are not one to want to short anything out of what they deserve...so here is what I would do. Rather than dining at several table service restaurants, maybe narrow it down to one or two that really appeal to you. If you go to
www.allearsnet.com they have all of the restaurants, menus and pricing for all of the dining options at Walt Disney World. By selecting just a couple that will fit within your budget, the financial pressure will be off and you can dine at ease knowing you can acknowledge your servers appropriately for the service they provided.
I hope this was helpful, have a great trip!