When you have two sofas or any larger seating arrangement a big coffee table might seem like the obvious solution. But also consider a pair of matching coffee tables. They will keep the focus off one large piece of furniture and let your eye move around the room more easily. One classic coffee table size is 48 by 24 inches so you can plan on that when thinking about your furniture arrangement. A large coffee table is often double that: 48 inches square.
Sometimes a coffee table that isn’t the standard height or width is exactly what a room needs. In this instance a very low coffee table creates a crisp horizontal plane in the foreground offsetting the long horizontal line of the credenza in the background. A higher table would have blocked the view of the credenza and competed with it; the varying heights add interest.