Suggestions

Things you can eat without cooking...

Bread/ cheese / salami sandwiches

Crackers and cheese and salami

Apple or other hard fruit

One square meal (2 bars = 1 square = whole meal)

Hard boiled egg

Tuna/ chicken and crackers (if you want to carry tins)

Bread and banana (watch out for squishiness in your pack)

Energy bar

Biltong and crackers

Other possibilities

Chips (for sparkle) - if that's all you eat, you will run out of energy