I think what Dean is trying to say, is that you will give the waiter three cards to take the meals off, but tax and tip will be expected for each of the cards, they may not be able to put the tax and tip on just one room key card and the meals on their appropriate card. Most meals the tax is not included, unless its changed from the last time we had the dining plan. We were 10 people and in a GV so we had all the credits on everyone's card. And yes, we did have a SIL that we were concerned that would eat the snack allocation for everyone. We actually had one person drop out, but I kept his credits (never checked in, but I picked up his key), as a buffer for that large eater! We treated a family of five to lunch our last day to use up that extra persons credits.
We're going TIW for our 2014 10 persons 14 day trip, and Dean, as Matriarch I pick up meals, Tickets (already purchased) and airfare, otherwise they wouldnt be able to go, and I wouldn't get these great memories.

There is a reason I work