Display One Div Multiple Times

I'm currently working on a browser based 2d multiplayer rpg using PHP and ajax. As the number of beta testers has increased, I have found that there is a significant amount of lag involved in changing maps (maps are 480x480px ea consisting of multiple images. What I would *like* to do, ideally, is only load each image once. So the first time I encounter "grass1.png", for example, it is loaded into div id "grass1", and never needs to be loaded again. My question is this, is it possible, to do the above, and then call div id "grass1" for each instance of the image?

This way, I could store all images encountered thus far. When the player left a map, all images would be positioned off-screen, and moved into the field of view as needed. I am already doing this, but there is a div for each unique object. (meaning there could be 10+ divs for the same image, for just one single map!). This would be much more efficient if I were able to call and store just one div per image, and just display it multiple times in multiple places.