The humid climate can cause a decrease in appetite. Thus locals tend to have many small meals or snacks though out the day.
Poisson cru is the way to go. Food trucks roulottes are also present though not like in Papeete.
Dairy products - Milk is not pasteurized and thus cheeses and yogurts are more flavorful.
Across the road from the ferry station is a pizza place well worth a visit. It's run by a French couple that speaks no English, but the menu has English explanations and the ham and pineapple are highly recommended.
There are also great pizza places just up the road from Club Bali and the Moorea Pearl Resort. Both are reasonably priced and you will get your money's worth. We hit either up when we have been in Moorea.
Baguette
The local bread. Make a sandwich with meat, cheese, etc.. Nothing fancy. Very portable. Along with a beer, this makes for good eats on the beach.