I would mount a bar countertop, 50 cm deep, at the height of 90 cm under the window, the length of that wall. Then I'd use counter height barstools at it. You absolutely do NOT have space for a U shaped banquette. I hope the view is nice. If not, then it's time to improve it!

Thank you for your response Carolyn Albert-Kincl, ASID.. But can't I custom build the booth to fit the space??

You might be able to end up with seating on 2 sides with the table in the middle, but the table will be quite small, perhaps less than 60 cm across. There are various articles online on how much space is required for banquette seating. I suggest you refer to them for additional information. They know more than I do about the space required.

What about a really nice corner pantry in the far back left corner and small bench with a throw pillow near the door?

Some options :

1. If you don't have a dining space, center the table you already have there and place some chairs around it. Place a slim hutch against the back wall for extra storage for dining-ware.

2. A mud room since it opens to back door ( if you haven't one at front), have a space for everyone.

3. Small home office.