Granite not only is good for counter tops, but is also handy for a table top. Usually table legs are screwed directly into the the table or into a bracket that is attached to the table top. Since granite is stone and not wood, it needs a different method for attaching table legs. The same way glass tabletops are attached to legs happens to work perfectly for stone tops, as well.
Spread the old blanket or rug out on a flat surface larger enough for your piece of granite to fit on. Place the granite on the blanket, good side down.
Determine the exact location for the table legs. Table legs work best when installed close to or at the corners of the table top.
Set an adapter on the spot where each table leg will be installed. These adapters are threaded and allow the legs to be screwed into place. Glue the adapters into place with the construction adhesive. Some adhesives go on white and dry clear so you can better see where you are gluing. Let the adhesive dry according to manufacturer's instructions.
Screw the table legs into the adapters that are glued onto the granite. Get the legs hand tight, but take care not to over-tighten the legs. This could damage the threads, the adapters or the legs themselves. Turn the table right side up.