Do a floor plan and make the smaller angled end of the room the dining area. As is now the table and chairs are wasting a lot of precious space. You can leave the t v where it is. With an app, have the screen become art work, or a simulated fireplace…. Put a sofa on the solid wall with floor lamps, sleek coffee table, with a colorful rug under, and two small swivel chairs to complete the vignette. Swivel chairs are valuable to your space, as they can turn toward both the sofa and the t v.

Once you have furniture in your space the chair rail will not be noticed on that side. It will not be the focal point. Your furnishings and artwork will be what people will see. Also, spaces that are completely balanced are not nearly as interesting as having a little asymmetry here and there imo.

Agree with lynartist get someone knowledgeable in to look at the walls. Shifting the color used makes a huge difference. I would not have the walls smoothed or made shiny. But there are all sorts of ways to approach this and end up with a great looking home. Consider moving the functions of the two spaces. A modern dining area with a fireplace, even such an ornate one, could be spectacular and marry well with a more intimate USED space for conversations, drinks, and even just solo book readin'! Making the switch would also de-emphasize the fireplace and allow it to look its very best. A bit of a paradox but look at many old European houses and you'll see it again and again. My other preference would be to have a wood refinisher take down the shine on the floor. Congratulations and I hope you let us know how this progresses.

Do you have anywhere else to sit to eat? Please provide us with a floor plan and measurements so we can help. Please do not do anything unless you have an overall plan (for a unified look). What is your style? If unknown, please put different styles in top search box, one at a time. Examples include transitional, traditional, casual, etc. How many people and children use this space on a regular basis? Usually a long narrow space is best used by creating two "zones" - one for a living room space, and one for ? - kids play space? What kind of foldable furniture are you looking for? tables? chairs? Is that for the children or for the adults?