Can be found in Decor > Clutter.
Ammo Case
Bag of Potatoes
Box of Cans
Canned Soups
Emergency Flashlight
Gas Can
Gas Mask
Jug
Loose Rope
Old Toolbox
Plastic Storage Bin
Standard Issue Blanket
Several of these have slots for you to set stuff on and the rope acts like a rug you can put under anything.