Just to share some tips that has really worked, and my assistant photographers can vouch for that. The key here is to communicate and get the helpers/coordinators/bridal party to help you out. I don't do the group shots, and I find that establishing some of these does help my assistant get his job done very quickly, and I mean 60 tables in less than 40 minutes is entirely possible.
1. Couples would have arrowed at least 4 helpers to help out during the group /table shots, usually right after the 2nd walk in/champ toasting.
2. The key here is to get 2 tables ready before we even shoot it. There's no waiting for anyone because emcee has annouced that if you're not at the table that's too bad (no matter how big shot you are, no one's going to wait for you to finish smoking or peeing)
3. No one is else is supposed to shoot, and the 4 helpers are there to enforce that. My assistant is to help make that happen. I always tell my assistants NEVER to take anyone's camera to shoot, whatever the circumstance is. When you've seen things like Uncle Bob's camera slipping off the hand of the helper (while trying to pass the camera to the photographer) into a bowl of drunken prawn broth, you'll understand why we don't touche other people's cameras. When one Uncle bob passes the camera to the photographer to shoot, the other people will follows, so think of how much time that's going to waste. Some of my couples does get their emcees to annouce that due to time constraint, the photographers will not be able to use anyone else's camera to shoot the group shots.
4. Setting the target time the group shots is to finish will help to get pressure points going and comeon, if 40 tables are going to take 1 hour 30 minutes to complete, which happened to one of my relative's wedding, that's almost half the banquet time. Ask your couple whether they spent a year planning for the banquet for that to happen.
5. Be firm, not kwai lan and do it with a smile. At the end of the day, you can't please everyone, but everyone has to know that you're paid to do your job well.