These are the things that you need during a circle, but there isn't room for them on the altar itself. They usually include things like extra incense (pictured here,) matches, corkscrews, extra glasses and plates, napkins, etc.
Normally, we keep them under the altar, where they are handy, but you can keep them wherever you can get to them easily, of course. Just try not to forget them when you are setting the circle up, because if you do you will have to "cut out" to get them later!