Physics, or sorcery?

This table is being held up by the weight of the buckets that are resting on it!

When I first saw this, I immediately dismissed it as easy to understand, but the more I think about it, the more my intuition fails me. I'm not sure what happens if you make the ropes a little longer or a little shorter, or the buckets a little heavier or lighter.

Table held up by buckets resting on it

(via That Book Smell)