NO PREP: A couple slices of smoked salmon. A few cherry tomatoes. Another fruit of your choice (apple, orange, berries, etc.)
Substitute similar things for variety: Smoked mackrel, whitefish, trout, or herring. Vegetables like cauliflower, broccoli or snap peas instead of cherry tomatoes. Fish not your thing (too bad cause it's VERY healthy) then eat sliced meats. Leaner is healthier.
ANOTHER LOW PREP OPTION: Charcuterie board. Make it in a big glass storage container and keep it in the fridge so all you have to do is take it out. Graze. Put it back. These can have almost endless foods on them, but choose wisely. No candy, Nancy! Eat some nuts.