DIY Retractable work bench in the toolbox.

All you need is a aluminium sheet or similar. Cut it 20mm wider than your draw, bend the exes 20mm material 90deg (10mm each side) and put two bolts trough it so the back wall of the draw can pull it out at the very end of the travel. The bend sides should lay on the sliders of the draw when the plate is inside. Be sure to curve the back edges of the bend sides so they can easily climb up on the sliders when you push it back in.