HAL appetizers are usually quite small: I am thinking of the 2 tiny crab cakes, the 3 medium prawns, the 3 pieces of bacon.
However, in talking to the Manager of the Pinnacle on our Noordam cruises we learned that on 7 day cruises a large percentage of the pax dining there are on freebies, mostly Have-it-all and 5 stars, with some TA gifts of a complimentary dinner. I guess the profit doesn't add up to much each night, so limiting the number of appetizers limits the loss.