Courtesy to the deales...
who spent a lot of money for their table. If the attendee wanted to make a sale type transaction they usually went out into the hallway.
Never really a rule just being fair to the dealers. Dealers probably figured the individual could get their own table. Sure this sounds petty for the
attendee who is just transacting for one or two chips, but it doesn't seem right when the attendee is trying to sell off a large batch of chips.
Sort of like not taking your McDonalds bag and drink cup into the Southpoint steakhouse and eating at their table.