It's a different way to do a pattern isn't it? There are two sets of boxes, one for each size. The numbers in the boxes are stitches-rows-times. I assume the number of sts to increasse or decrease, the rows to work this on and the number of times.
It's a sweet pattern. It mighjt be worth going through the diagram and writing out the directions so that you're sure to understand the whole thing before starting.