Yes, the chart is for you to keep track of which ones you have cut. There's a note on it someplace that says you might not be able to get the first (longest) one, depending on your strata. That's not a problem, just cut the one that is the longest your strata allows.
As you cut, DON'T go all the way across your strata. You want that piece to remain intact so that you can then cut more wedges from the other side of it. So you have to cut down the length, across that little top, then the other length. If you have a small rotary cutter, it really helps in cutting only the amount needed across the top (narrowest) part of your wedge without going past - if you cut too far, you won't be able to cut a wedge from the other direction.
Does that help?