Snapblade 18mm razor, sharpie, blistex (superior to balm/stick in every way), bandages and alcohol prep wipes and triple antibiotic, Sawyer mini filter and a vacuum insulated bottle, and a towel - you never know when you’ll need a towel.
Oh also an extra mask, couple napkins, some new folded up tissues, and earplugs.
What? Why? I used to do that all the time. You cut it up, and take it with you. Like they said, it saves dishes. Even when I was a teenager at my friend’s house, we’d make a frozen pizza, take it out onto a cutting board, then just stand around and eat it off the board. Good memories.