For chair scoot and sit space, I'd follow the guidelines for a rug - 4' all around. Then you want to be able to navigate around the table while people are seated, so add another 18" all around. Are you locating the table at the end of the galley? Maybe you could use a banquette on one side or in the corner https://www.houzz.com/photos/3rd-street-bungalow-traditional-kitchen-austin-phvw-vp~214425

I would wait for the rug, until you have the shutters up and your furniture placed..it may take on a character of its own and you'll want to compliment. My first thought though was to coordinate with your kitchen and incorporate some black, with a black/beige stripped rug, which would be fun with the wallpaper and perhaps paint your chairs black, add the shutters and you could paint the window trim black and add a large black chandelier.

Hi Jennifer K, thanks for your comments. The photos you have posted are really lovely but not really suited to our environment and house, which I know is impossible to tell from one photo. We have built a modern farmhouse on 10 acres. That room looks out to beautiful green countryside and the river below. The dining room is a bit of a feature and is completely different to the rest of our relaxed lodgey style house but I don't want it to be too modern, if that makes sense. The photos have given me a few ideas so thank you so much for your help!

Everyone has some valid points and so I would also recommend moving the clock to the kitchen wall and place the wall unit under the mirror. Centre with the table with the additions of some artwork each side if the clock with wooden frames to match the clock. Find a low piece of glass or pottery or a runner to tie in the grey shades. I presume u have a grey lounge suite. Change the lighting as to what was suggested by People Space ARchitects.