A skinny buffet would visually make room. I have seen them used so I know they are out there. A narrow table would be nice too, but I bet that would have to be a special order?

It sounds like relocating the china cabinet will make the room function much better. Is there a place in the living room you can use it? I've seen this done where the cabinet becomes less of a china display space and more of a decorative pieces display space. A narrower table would be, perhaps, 36" wide and that would get you only about 6" more of moving around space, which, I would think, wouldn't help all that much.

Can your table set at an angle? I've done that before so the narrow areas are at the corners or in your case the curve where no one sits.

Thank you all for these good ideas - I'm still debating. Since I have a small cottage I'm trying to see if I can move the cabinet somewhere else ... not very easy with my space.

If you post a picture of the room you me able to get even more ideas for using what you have or doing some changes.

Yes, post a pic if you can and yes...try to move the buffet. :)