It might also help to know which room in the house this area is in (living room, den, entry hall/foyer), as well as what/how the room and the area in the room are used for. Will this area actually be used or are you just trying to fill up a space you consider empty? And in either case, are you able to "shop" your home first before buying anything new?

Okay. My 2 cents. It appears that the dining room is a bit squishy. Lots of big furniture. My thought would be to remove the sideboard, put a banquette along the wall and shift the dining table over. This is a tad fancier then what you are going for but this is right beside a kitchen peninsula...same layout. I think they shifted the chandelier over so it is centred with the table. If you search for "banquette dining" on PINTEREST you'll get lots of inspiration. Just a thought to give you more breathing room if desired. :) The balance between the beautiful banquet and the open chairs would be perfect (in your style).

Three patterned carpets, one house. NOPE. Not even three colors, solid! Unless you do favor "choppy" For those who like changes between rooms ( rugs) between rooms? You need the unifying aspect of hardwood BENEATH those rugs. Just one reason why hardwood flooring is fabulous. Yes, EVEN on a second floor. No your toes won't be cold : )

Thank you to everyone for your input! I wanted to follow up just in case anybody else is struggling with the same decisions I was with a curved expanded bottom couple of steps in an old staircase. Despite some of the recommendations above, I did go with plaid and I absolutely adore it. So it can be done, but to get the lines to continue to flow in a consistent way took a ton of planning and hours of labor. But I love how it turned out. Thank you again for all the help And suggestions!