Purchase glass glue designed for your style of tabletop glass. For example, buy clear adhesive if the glass is clear and you don't want obvious gray or white strips between the seams. Purchase ceramic glue if the table is ceramic glass.
Put on a pair of thick gloves that are difficult to cut, such as leather work gloves. The broken glass is very sharp and can easily result in serious injury.
Place the pieces of glass on a flat surface. Arrange them together like a puzzle so they're in their correct place. Cover the edges of one piece with adhesive, then press it together with its matching piece. Hold them firmly together until the adhesive dries enough to keep the glass together. Repeat with each broken glass fragment.
Allow the tabletop to dry for the time specified on the glue packaging, then place the tabletop onto the table frame.