You can (visually) expand a small dining room by keeping the color palette to two or three colors. Soft and light does it. A glass top table gives an airier feel. Go with arm rest free dining chairs and a simple pendant light overhead to minimize bulk.

Keep any artwork simple (you can dress them up with nice frames) and keep the floor clutter free by removing any side tables, plants, dog bowls, etc.

a light material rug, like jute, can pull the elements together.