My kids like peanut butter crackers. We make them at home with natural peanut butter. They also eat gogurts and fruit, sometimes pretzels, sometimes carrot or celery sticks. My kids love peanut butter so they eat a lot of that in their lunches. Sorry I don’t have any original ideas.
My daughter likes hummus with carrot & celery sticks and cucumber slices. We also have a wide mouth thermos and sometimes send home made soup and crackers. She also likes fruit and cottage cheese.