It's common to see and attend weddings at a wedding hall... it's really an efficient event with pre planted flower-tossing-bouquet catcher to presentations and group pictures in 50mins tops for each couple before the next wedding event starts approx 10mins after tidying up the hall.
You leave your angpau at the desk in return for a buffet coupon that you can claim your meal at a general food hall later.
In there you get to rub shoulders with the former, present and latter guests from the multiple/simultaneous weddings.
Overall...it's short and
sweet swift with most guests heading straight to the food hall instead.