This looks really tedious to do by hand. Is there an easy way to break up images?

Both Adobe's ImageReady and Macromedia's Fireworks have Image Slice tools. These will easily let you split up an image into several parts, which you can then save into a table. Both programs will create the HTML for the table, and create several image files (one for each of the image chunks) and place them in a folder of your choosing.

If you are generating images dynamically, there is probably a way to automate this process. Perl and PHP will let you alter JPEG files if you have the GD graphics library. And if you are writing Java servlets, the drawImage() and clipRect() functions should prove quite useful.