A lip edge or tray top on a coffee table is always a smart choice if you have a tendency to spill your coffee or have kids that will be using the coffee table for snacks and drinks. They’re also good if you entertain often and don’t want to worry about red wine getting spilled on your carpet. Coffee tables should be the same height as the surrounding seating, with 18 inches being a good average (although it will depend on your furniture). If you select a coffee table with a lip, make sure the lip isn’t higher than the adjacent seating, or you’ll end up hitting your drink against the lip when you try to set it down. The idea is to put your drink down, not up.