At some point in time everyone has bought a roll of wax paper. Maybe you thought it was parchment paper, maybe you only bought it because your mom always had a roll and you thought you needed it. It could be for craft projects or actual kitchen use, but either way, most of us have a roll buried somewhere in the depths of our pantry.
To keep the top of your kitchen cabinets (and tall armoires, bookcases and storage units) clean, simply tear a sheet the same depth as the cabinet and let it sit. It will collect the greasy, dusty goo that collects and then every few months you can change it out and ditch the collected junk. Easy peasy!