Earlier quoted context omitted.
Yes, most of them are full board. But you just don't want to go back to the ship only for lunch, so you have lunch in the city, where you can have a taste of the local cuisine.
Potentially. I suspect there's a lot of cultural and generational norms wrapped up in that though. A ship full of Swedes may prefer to return to the boat to eat, a ship full of Spaniards may all want 3 course meals on land, that just makes it harder for the host city to predict demand.
So at least for this company most people did not incur food costs on board for lunch (non the less having paid for it with the package deal).