Mike's comments made me visualize one of those blender/mixer mounts--would be pricy unless you ran across someone tossing a set a cabinets!!Don the problem I see with mounting it on drawer slides is the working height of the top. I have enough problem with working on the top of a normal workbench but it could be on a drawer mounded shelf where it could be pulled out and raised up onto the top of the workbench. Problem there would be the top of the workbench would need to be cleaned off before you could use the table.
Oh one more possibility it could be hinged to your workbench on the end or back if your bench is not against a wall and mounted right would be higher than the top of the bench when in use or could be mounted where it is flush with the top. with the addition of the T-track it could be used to assist with glue ups. I kind of like this idea because both of my workbenches are on rollers and are usually never against a wall.