I use a wine bottle tote as a snacks bag: water bottles take two of the six slots, a banana fills the third, and an orange in the fourth. That leaves two cubbies for Ziploc baggies of nuts, dried fruit, etc.
While these bags are not the ideal shape for Tupperware sandwich boxes, it’s still a darned good use for something otherwise useless for groceries (how much wine do you buy at a time, anyway?).
I have used one of these carriers to corral older infant and younger toddler toys in the car. This sounds like a great tool for the park, beach or playing field.
For summer road trips, you can use a super-sized version of this strategy: Pack road trip snacks and supplies in a divided wine carton.
This shape of carrier would work really well with a past snack hack: create single servings to teach portion control and increase independence.
More: Snack-packing tips and techniques.