My area is not nearly that big. You will definitely be able to store your rolled leather under your cutting table. I placed a work bench (2x6') against a wall and use it as my work space. On the back edge, against the wall, I have my wood blocks holding my stamps and other round metal handled tools. On the wall, directly above my blocks, I have some 1x4x6' pine mounted with leather loops to hold my edge bevelers, round end punches, etc. Above that are 3 shelves 1x15x4' I store my threads, and larger bottles of dyes, glue can, etc.
Beside the work bench I have some of those plastic stackable drawers for hardware, misc tools. I also have some under one end of my workbench for work in process and small pieces of exotic leathers. On the other wall is a 3x6' folding table my wife uses for her sewing machines.