I think that you are looking at DIsney DIning as you look at dining at home. It is two diffeent animals. WHen you dine at Disney you make an ADR, and it is not a reservation. It is like call ahead at Olive Garden. A place in line that you reserved. You cannot just add a persom or two, they also need their place in the line in order to be granted access to the restaurant. If you want your friends to join you, you need to find that ADR that coincides with your own, but even that will not allow you to be seated together. You may, but then again, you may not. The only way they can be seated with you is if you can increase the number of people on your ADR. I would either try to do this, or if celebrating together is more important than the location, change where you eat.