That is a really cute interpretation of that quilt block! ^_^ I think I recognize the apple fabric, too. Is the block from Japanese Quilt Blocks to Mix and Match, by Susan Briscoe? I have been eyeing that book for a while now. Do you like it?

You might look into getting a piece of non-slip foam material (I'm really not sure what you'd call it) from a hardware store, and putting that underneath your quilted mat when you finish it. That should keep it in place. :)