Run to the big screens and look away from them. Run to the barrier in the top left corner and knife/shoot the bottom two pieces of glass off it.

Rebuild it and you can jump between the two planks of wood.

Jump on to the door frame and jump onto the small table. You can then sprint and jump onto the big table.

Zombies then cannot hit you!

Note: If you are on the big table, whatever you do, don't go to the edge as zombies will hit you.
Tip: If you see a power-up close to the edge of the table, don't jump off, kill all the zombies in that area and then go as close to the edge as you can and you should be able to get it.