Round.

I'd suggest a round dining table with a pedestal base -- something that is not too large for the space. Upholstered chairs in a simple stripe or interesting pattern.

Without seeing what the other spaces that both walls connect to, I'd suggest painting both walls in an accent color -- something like Benjamin Moore oyster shell.

Move the mirror to the short wall. It will reflect some light into that space -- plus, no more view of your kitchen sink!

Hi Read....I would help if you could take pictures of different views of the space.

Hi Matilda, I am NEW to this site and am not sure how to upload photos to Houzz, so maybe I'll attach them below? Here are more views. One of the pictures I was hoping I could scale down to fit my corner. I have seen square banquettes accompanied by round tables and it seems to work. Thank you

Oh and the living room is a whole other project. I just have to get the dining area done.

Since there are no windows in this area, I thought about replicating the window look using windows with mirrors or even the landscape films for windows, on the wall with the mirror.

Hi Read...The pictures definitely help. if you will give me the dimensions of the corner walls
and the space between the mirror wall and the kitchen counter, I can tell you if a built-in banquette will work. It looks like the living room has dark leather, and in small areas it
takes up visual space, I would suggest more contemporary lines and upholstery with texture, the wood floors are a big plus. Where is the natural light source???

Corner walls 7' 10"
Distance from mirror wall to counter 10' 4"
I just realized that my chandelier is in the middle :( so I'm thinking the banquette prob won't work:(
Natural light from 4 windows on wall opposite of wall w/o mirror.