More views of the room would be helpful.

When you're trying to figure out what a room needs think about these things:

1. What is the function of the room?
2. Is it a high traffic area?
3. How many people use it and for what?
4. Do you eat there?
5. Do you need all those tables?

Just basic questions but as soon as you know what you want to do in your place, you'll have a better understanding of how to design it.

Okay, if it were me, I would start by making sure the TV won't get too hot over that fireplace. Second, those on either side of the fireplace might want to be filled. I would suggest shelving that makes you happy. Shelving that displays conversation starters, unique ones that vary in sizes. The art work is really high up, I would suggest lowering it and incorporating it into your design. You could also add two console tables there and maybe mirrors?

Get enough seating to comfortably accommodate your guests.