Google Maps too much points

I've created a page where some records can be shown into Google Maps
Actually only records in the grid are visibile in the map

I have crazy idea to have the other way round: while zooming the map update the grid to show only records of points visibile in the map.

I do not have any clue on how to do it and even if it is something possible using stardard grid.
My idea is to use a Javascript grid and connect it with the map in some way depending on the zooming level of the map.

Any idea?

Thanls a lot
Eros