From page 19 of the rulebook: "Some powers and abilities (such as Super Strength) allow a character to pick up and hold an object, and then use it in close combat and ranged combat attacks."

That paragraph allows me to use an object in close combat attacks. Quake make a close combat attack against every adjacent enemy model. The rules then go on to say that I must use the object in the atack if making a close combat attack against a single character.