I think I am with zennia and Tapper on this one. Cut the blocks apart. Now, on graph paper, draw out the size of your top. Then, decide where you want the blocks. I think zennia's idea of using the smaller ones as cornerstones is really neat. You might want to add a narrow black sashing to all sides of the blocks just to set them off. When you are deciding on the size of the 'filler' blocks, don't forget to add that amount. You could do something as simple as 9 patch blocks to fill the spaces. I love the bottom three fabrics together. Remember that you could make the 9 patch blocks as big as you want too so that would show off the pumpkin fabric.
Let us know what you want as a finished size and maybe we can help with the math.