You’ve spent so much money on just getting to Hawaii, why pay more to sit inside a restaurant? Weather permitting, you should be outside on the grass! Or on the sand. Or at a picnic table.
Borrow a sheet from your hotel to sit on or use as a table cloth, as well as glasses and silverware. Chose the most appropriate place from your “sights to see” list and make a lunch or dinner out of it by ordering take-out from one of the local eateries.
Having a picnic outside near a fun destination will give you an “insider’s view” of both that sight and the local culture.