here's a dodgy workaround:
set the picture as your desktop image, and have it set to tile.
then clear everything off your desktop and take an image of it. (Shift Apple 3)
(or contact the people who suplied the graphic, and try to get a bigger one?)
In PS, using layers, dupe and move multiple copies of the image to make one single row of images. Then merge these layers to form one layer with a row of 1x1s on it. Now dupe this layer as many times as you want and shift each to make a 10x8 box.