I would hope all rooms have a rack with each table. Usually there's even a place to store a triangle right on the table.Most rooms have the rack and quarter inch thick’s worth.
They are very cheap to make. You can call up advertisers who make signs or window signs. They can print up a bunch for very little and cut the inserts for you.
This is advice for owners if they want to go this route. It would end up being a disposable product to the public.