Do all 10 chairs need to be at table all the time or can it be 8 chairs and 2 you bring over from somewhere else for large sit downs? DIAL UP YOUR CHAIR sizes to be proportional to table so, as to not look like child size chairs. Restoration Hardware furniture is over sized and generous proportions compared to many other retail sellers. Just any chair could be easily dwarfed by the RH table and look tiny. Here are a couple of my favorite modern chair makers KNOLL Brno flat bar chair which can be bought at auction and recovered in leather or vinyl of your choice and David Edward Furniture made for corporate, resort and colleges and available through dealers, I am showing here as a "host chair". Other "host" chair items possible of course. I just like this one.

Like the previous comments it depends on use and the design of the light fitting itself. Also if the light has a narrow beam it may need to sit higher to throw a wider beam to light up the area you need lit up. Generally you would put it above eye level so that it doesn't obscure your view when standing. More often than not it is just a matter of where you think it looks best, most pendant lights have good adjustment so before its installed have the electrician hold it up for you at different heights and see what looks best.

It might be worth while to consider the rest of the space also. Your breakfast bar/kitchen is located quiet closely to your dining table so depending on your kitchen space (apologies, I can't see too much of your kitchen from the photo) you might want to think about the overall style you want to achieve for you entire open plan space, and select pendants that would work for both your kitchen and dining. This is a project I worked on recently that shows how two different types of pendants can work harmoniously in the one space that is most similar to your kitchen and dining set up. Keep us posted on what you decide!

Carol, what did you decide on? I'm having the same dilemma now and am curious about what you went with. My table is 2100 x 1040 and the two lights I'm considering are 600mm or 800mm in diameter, and very minimalistic. Ceiling height 2.7mts. Would love to hear what you went with and whether you're happy with your decision.