When sourcing granite tables, the thickness of the slab is paramount; standard commercial tops should be at least 20mm to 30mm to ensure structural integrity. You must verify the Mohs hardness scale rating (typically 6-7 for granite) to guarantee scratch resistance. Additionally, ensure the surface has undergone a professional sealing process to prevent liquid absorption and staining, especially for hospitality environments. For outdoor use, confirm the UV resistance of the resin fillers used in the stone to prevent discoloration.