"地图坐标方格" can be translated into English as "map coordinate grid" or "geographic coordinate grid on a map".
"Map coordinate grid" is a concise and commonly used term that directly refers to the grid system on a map used for locating points with coordinates.
"Geographic coordinate grid on a map" provides a more detailed description, specifying that it's a grid system for geographic coordinates on a map.
In most contexts, "map coordinate grid" would be sufficient and more widely recognized.