Heh, cute. I remember I wrote a program in DB Classic many many years ago that would convert BMPs into HTML pages using one table cell per pixel (back when CSS just didn't, well.. work). It worked nicely for little sprites and things, got insane on large images - bit like your CSS version would. You could SO optimise your CSS if you wanted to shave off some serious bytes
Try deteching when two or more similar "cells" touch each other horizontally, then change the widths, etc. Wrap the top px in a single div row block, etc.
Cheers,
Rich
A great many people think they are thinking when they are really rearranging their prejudices.