At ds's school, we're asked to bring snacks in for abour 24 kids for the week too.
Usually, it's fruit, cut up veggies, mini bagels, hummus and pita, crackers and such.
I was told a bag of apples, a big bunch of bananas, two boxes of graham crackers, and maybe some hummus and pita are more than enough. I brought it all in on a Monday morning. The school prepared it all for each day.