If you can’t turn the table, I would get 2 more chairs, put 3 on each side, get rid of bench, no chairs on ends, there is not enough room.

Make a floor plan of the room with measurements and windows labeled. What is the size of the table. I don't think anything besides the table will fit and @Jeanne Cardwell's suggestion about turning the table is good. Large art on the wall. What is on the other wall? I would consider getting a rug. Raise the curtain rod closer to the ceiling

Can you add more images of the space? It looks like if you turn the table so the head of the table is in front of the windows the space might feel less cramped. You might also consider a new chandelier and a rug to help ground the space, along with some artwork to help the space pop. The image below is one of our recent designs. Please notice how the dining room table doesn't feel cramped, the chandelier goes with the ascetic, and the rug helps separate and ground the space.

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I would turn the table, and maybe add a rug. Is that a buffet against the windows? Not sure that is the best placement for it.

You might try a rug, some artwork, and a new chandelier. Here are a few of our recent dining room designs which also might help you more with your current dilemma.

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