I think you need to better define your question/dilemma in order to get constructive responses

My deck is 4.1 x 2.5m and I found it was too narrow for a table and chairs so we placed them on paving further up the garden. It’s fine if not in use. I know yours will be a little bit bigger, but I found that when people were seated no one could leave the table without climbing over another person, if you get what I mean! Go with your instinct and go larger 😊 This is where the table ended up.

I really want to find the source of these table and chairs. Any help and hints would be greatly appreciated.

So lovely that you wish to restore your grandads furniture. It’s amazing how good dark painted furniture can look. I think painting it charcoal grey, black, navy or dark green will fit in nicely. Painting furniture isn’t difficult, but it must be done properly. So a light sand, wipe down and then paint on 2 coats of primer and 2 coats of top coat such as eggshell or Satinwood. It is crucial to let each layer dry thoroughly and cure before applying the next. Best to leave days between coats rather than hours. You could add a seat pad to the chair. Dunelm sell them or Etsy have a huge range. Here’s some painted furniture to give you an idea of how it could look.