If your old couch is looking the worse for the wear and you can afford to reupholster it, the result will be a couch that looks brand new. It is especially worth reupholstering a couch if it is an antique. You can completely update the look by using a modern pattern and material.
A cheaper option is to purchase a slipcover for your old couch to hide any stains and worn areas in the original fabric. The benefits of using a slipcover include the ability to change it if you choose to change the dining room's decor and you will be able to machine-wash the cover when necessary.
Dining rooms that are large can accommodate both a dining table and a separate seating area. Place an area rug on the floor and add a chair or two adjacent to the couch so that your guests can enjoy before- or after-dinner drinks in comfort. Add lamps for soft lighting and coffee or end tables so there is room to set the drinks.
A creative way to incorporate an old couch in your dining without sacrificing space is to use it to replace some of your dining chairs and create a cozy banquette. This an ideal solution for a smaller dining room if the height of the seat of the couch will work with the height of the table. Place the couch against a long wall and move your dining table against it. You will still need chairs for each end and the opposite side of the table but several guests will be able to sit comfortably on the couch.
Do away with your dining table entirely and create your own version of a home dinner theater. Install a flat-screen panel on one wall of your dining room and invest in a large coffee table or a decorative set of trays so that you can sit on the couch and eat while watching TV. Use some of the space gained from removing the dining table and convert a portion of the room into a wet bar.