There should be at least 30" from the edge of the table to the nearest wall. This allows for seating and exiting / entering the seat. There should also be a minimum of 24" per place setting. Other dimensions are listed in the article below. Here is a link that might be useful: table dimensions

Got it, thanks! I think you're then left with a usable kitchen that roughly 13' x 13' if you expand cabinetry on the slider wall. I definitely would relocate the refrigerator down to the end of wall B so it's not as close to the stairs to DR. The L peninsula will provide extra cabinets and seating. The J (squared off peninsula) would be better if you end the J roughly where the current island ends. I prefer the J to the L as that would allow conversational flow with wrap around seating if you do a 90 degree. Since you have the room, I'll toss out a 3rd option that I'd really prefer: consider a circular seating area on the long leg and not placing chairs on the return. If you add a window on the sink side you won't have a lot of uppers, if you want any. It looks like you may be able to add one upper there. Would you consider an island cooktop with DO? If so, the ovens next to the RF would allow you to have a complete run of uppers on the DR wall side and uninterrupted counters underneath.

I would push chairs in as far as they comfortably go. I was just noticing that the seats are not completely under the table and still reach nearly to the center column. They may be extra deep as well as wide. That would also make the table seem smaller. I pulled up Wayfair to check chair sizes and they have several styles similar to what you have chosen but with an 18" width. You might want to look there if you want something similar to the wider ones.

The only thing I see wrong is that the table is way to close to the wall. Center it in the room under your lighting. When a table is off center like that it just makes the room look small and cramped and wrong even though you leave a large walking path on one side. You should be able to comfortably walk completely around it. If getting a smaller narrower table is needed to do that get a smaller table