Table lamp... only minimally effective if the fluorescent bulb breaks and glass shards and/or electric sparks have any effect.
But if allowed 2-3 seconds to think, behind the lamp (and a couple other generally ineffective items) are two Coca-Cola glasses (you know that distinctive shape), one filled with multi-colored Flair pens (also ineffective; ignore them), the other containing various office items including THREE rather large pairs of scissors. Don't know why/how I acquired three of them, but now I know why they're there... to repel any attackers not made of rock.
Yay. I'm going into the zombie apocalypse wielding a paperback copy of "The Saga of the Volsungs". Zombie is papercut and pissed off.(Oddly enough, if I were to pick up the item to my right, it would have been a back scratcher as well.)
An 18 inch solid steel bar, wrapped in black electrical tape. It's about 3/4 inches thick. It was used to jack the main drive shaft of a five color printing press if the press got a paper jam. No I don't keep it for zombies. It's here for living assholes. But it would work just fine for the undead type.