Microsoft Access help

I’m making a guest list for my wedding and I have done the follwoing. one table with all the names and address and how many people are in each family and a field that connects to a second table with just table numbers in it. so this way I could go to this certain family and choose a table number for them to sit , so I’m able to choose the same table number for more than one family. Now I would like to make a query that would tell me how many people are at each table and warn me if I go over a certain limit.
Thanks in advance