OP, to be serious, when tables with a base much smaller than the top is installed in a bar, club or restaurant they invariably have a heavily weighted base in something like cast iron or thick steel plate, or they are bolted down to the floor to prevent tipping. Any table that kids or unsteady adults (elderly, disabled or drunk!) can tip over too easily is hazardous and should not be offered for sale. Should the vendor refuse to take it back you have recourse to the distance selling regulations which your local consumer services department in your council will either advise you on or may even take up the case on your behalf