Does a light fixture for a round table have to be round?
The most important fact related to your question is that these types of issues are ultimately very individual and personal decisions, and there is no one or absolute answer. Most designers will tell you that either a square or round fixture is appropriate over a round table as long as it matches the general style and finish of the overall design concept in your space. In today’s design climate, it is very appropriate to mix and match styles and finishes.
by: American Lighting Association (ALA)