No one has mentioned much the new Super Walmart right near Costco in Kapolei as an alternative for a few grocery items. It may not have quite as much groceries as Target, but they do have some.
Remember, all the stores (Target, Coscto, Walmart, and Safeway) carry beer, wine, and hard liquor in Hawaii. I hate that here in Maryland we have to go to a separate liquor store!
We cook almost all dinners in during our two week stays at Ko Olina, but do eat lunch out often when we're running around.
If you are up in Kailua, definitely go to Willow Tree (right near the Safeway grocery store) for their Korean food! My husband is Korean, and we've always loved that restaurant (we've been going there since 1995). Their portions are huge. It's nice that I have an 18 year old boy to help me finish my food!
If we have extra food at the end of the trip, we used to give it to the housekeeping. Now at the Marriott (timeshares), they have large bins in all the lobbies to collect for the local food banks. Those bins fill up quickly! I like that idea.
We bring one suitcase with spices, small condiments, and also don't forget it's nice to bring things like plastic food storage containers (for leftovers), aluminum foil, baggies, drink mix like Crystal Light (I keep a pitcher in the fridge always, then we drink more). Bringing these things helps cut down on our first day shopping (usually we hit Target the day we arrive for essentials, then Costco the next day to really stock up),