This is a bowl of honey. It's here on the altar to remind us of the sweetness of life. Not all traditions use this; in fact, we didn't use it either. But it comes from a very old tradition, and it has grown on me! Along with the sorrel on the other side of the Maiden candle, it reminds us that along with the bitterness that comes into every life, there is always sweetness.
After the circle, any leftover honey may be kept, and used again for the next circle. Do keep it separate from your regular stores of honey, though.