I understand your point of view but it is a bit late to start all over again.

Do you have an advice for my current situation?

I would go with same colour counter top as above as it ties in with backsplash and cabinets. Thus, option number 4.

@momof5x thank you a lot. That makes a lot of sense. I think it helps creating a focal point on the mosaic also.

Here is the updated version of the design.

What would you recommend for a dining table there?

If you are going with a grey toned countertop try "concrete" caesarstone , "cement" caesarstone or "stone grey" caesarstone which are quartz options.

A good tip we always like to tell customers is that everything in a room should melt together and should "just fit". The backsplash shouldn't be in your face and extremely noticeable. People should love the room not an individual feature. So when trying to match the countertop, try to find a countertop that picks up on a few colours from the b/s as well as ties in the cabinetry colour.

Hope this helps.