A.Scott's Workshop

Well after seeing photos of other woodshops I thought it best if I cleaned and organized mine. As of now I just finished putting together a 48” wide x 17” deep x 34” tall work table with a place below to hold old tool boxes. I am planning on making another table with the same dimensions. I am making these tables this size so I can move them around or if I move to a different house I can take then with me.
My problem is that I would love to make a rack on the wall to hold wood above these two tables but my walls are centerblock and I would really prefer not to put nails or screws into the block walls.