There are a couple of ways to do this, it depends on whether you want to have adjacent squares or squares with space between them. I would go for the adjacent squares, because it is much simpler.
My solution would be to use pcolor and a colormap with gray(2) , so I get white cells with black lines between them. By using pcolor you could add color to your squares if you want. You just change your colormap range and argument to pcolor, see pcolor .
For the text I would simply use text in two nested for-loops, offsettting the text into the center of each cell. Note you will have to align the text using the argument 'horisontalalignment', for more information see text.
