There are a couple of glass shops (Crystaleria) to be found on the main road down to Puerto de Mazarron
Our glass table broke last year, and they fixed us up with a new piece.
The shop we went to was in the same area as Na'ura and Gines Navarro.
Not too sure about their English, so suggest you work out what you want, and how to say it in Espanol before you go
You'll need to provide the dimensions of the table and thickness of the glass
If it's a big table, you might need it delivered
Good luck
PB