There will be several different food trucks serving different food at the show area. Read more in this link. 

There are further nearby restaurants, near the show area.  Those are open both during the opening hours of Open Boatyard, as well as in the evenings after the event.

One of the restaurants, Hotell Varvet (formerly Sjögården) is just across the street from the area of Open Yard. 

Further restaurants are situated nearby on walking distance.

Reservation for changes

All three restaurants also serve alcoholic beverage