Spread a 1/2-inch-thick layer of fine grout over the surface of the table top using a trowel. Apply the grout in an even layer.
Select one color of mosaic tiles to become the swirl. Press 1-inch-wide glass tiles halfway into the grout starting in the center of the table, then apply the tiles gradually extending outward around the table top.
Press different-colored tiles around the swirling tiles to fill in the rest of the table top. Space the tiles 1/8 inch apart.
Spread a 1/4-inch-thick layer of grout over the top of the table to cover the tiles. Scrape off the excess grout with the trowel, which fills in the spaces in between the tiles but scrapes the grout away from the tops of the tiles.
Wipe off the tops of the tiles using a washcloth, then smooth down the grout in between the tiles using your fingertip. Allow the swirling mosaic table top to dry for 12 hours.
Paint clear sealant over the entire table top, then allow the sealant to dry for eight hours before using the mosaic table.