Ours is biggish, could be a home office, really.
We keep it unheated, so...
Larder, overflow food, especially anything might go off if not cold.
Washing machine, dirty clothes, detergent, laundry baskets, iron, ironing board, pegs.
Lots of packaging/parcels for sending parcels/fragiles (I sell for charity). 2 big drawers of stuff I sell for charity (there is a lot more upstairs, too).
Spare binders, plastic envelopes, empty box files.
My skates, wrist & knee guards, spare skate stuff.
Spare shoes, hiking boots, spare waterproofs.
Swim kit, gloves, hats, sorted by sizes (kid, adult) & type (cycling, wooly). Sun hats, beach shoes.
Spare recycling, rags, items I am trying to give away.
Candles (we get power outages often), straps, lanyards, string, curtain rings, paper maps, product receipts & warrantees
Some spare ... car bits, some spare chairs, spare soaps.
DS's smelly 3d printer went in there when we had that.