Maybe something like this.

Picture of the room from ALL angles would get you more help. That pony is but one part of the room.

One option is to replace the railing with a built-in that can be a bookcase/cabinet for the living room or a sideboard for the eat-in area.

I could not find a great photo but here are two examples:

IMO irst decide what you need there and then remove those spindles and have an actual wall done. Those spindles make that space visually way too busy to put anything there. I love the idea of practical built in then no reason for much else t all and you gain some nice storage

Not every space is crying out to be filled.

The quickest solution is to minimize the business of the spindles.

I would paint the spindles black, even the base trim below the rail.

Leave it empty, you already have a light space and I wouldn't want to block the clock, it's a great focal piece, just isn't seen with the visual clutter of a dated spindle.

From what I can see of your home, it looks fairly traditional, so I don't see the balusters (spindles) as being dated or visually cluttered.

But you do need to show the entire room to get better advice.

Due to the clock, I’d avoid adding anything too large. If anything, a big plant would be nice and consider painting the spindles black.