You can absolutely use a storage bench as a coffee table, as long as the top is relatively flat and stable and the proportions work with your sofa or armchairs. This type of arrangement works best if you are storing infrequently used items in the storage bench, or if you are the kind of person who believes a coffee table is a useful surface for temporarily posing your coffee, drink, book, or tablet, rather than a showcase for knick-knacks and seasonal vignettes, since you don’t want to have to undo an elaborately styled coffee table every time you want to access it.