We had a situation a few weeks ago when all my tables turned up within 20mins( they are normally staggered over 2 hours).We seat 22, have one chef, one kitchen helper and one waiter.My solution was to go into the restaurant and give a speech about how we had obvioulsy made mistakes with our bookings,some of you have turned up at the wrong time etc etc and that service would be a little slower than normal.Asked if anyone had a plane to catch? Guests responded so well, totally understanding.We then had the most crazy service, but the food was good, and the tips even better.My advice is to be upfront with your guests, if they know whats going on , they are more likely to be cool.