1) Take the knife in hand.
2) Beat a knife into the wall.
1) Take a knife or other object that you can beat in your hands.
2) Go to the wall.
3) Press LMB frequently.
4) Clamp the ALT and look away to another corner / part of the wall.
Table without collision:
1) Take an object that you can beat in your hands.
2) Sit on the nightstand, which is shown in the video.
3) Click LMB.