Assuming you’re car camping:
sachets of tommy sauce/brown sauce, available from cafes/restaurants, often for free.
some washing up liquid decanted into a small container (boots do some little bottles which are ideal for camping quantities of stuff).
Dishcloth for drying your stuff before you bring it back to the tent.
Tupperware type container to keep all your edible stuff in or better still a coolbox.
A couple of spare tent pegs for when you bend one and lose one.
Small dry bag, keeps your stuff dry (obviously) and doubles up as a pillow.
But better than that would be a real pillow.
A few metres of 3mm cord. useful as a clothes line if stuff gets wet but can also double up as guy lines etc.
Bacon. Nothing better than frying some bacon in the tent porch.