A Swiss Army knife was a multipurpose tool.
Ace found a Swiss Army knife with the letters IC in a sofa in the Doctor's TARDIS. (PROSE: Cat's Cradle: Time's Crucible)
The Seventh Doctor carried a Swiss Army knife with him while in Hong Kong. (PROSE: Bullet Time)
The Eighth Doctor used a Swiss Army knife to break out of a room on the Quetzel. (PROSE: War of the Daleks)
Melanie Bush carried a Swiss Army knife with her in her purse. She used it to break into Sheffield Hallam University. (PROSE: Instruments of Darkness)
The Fifth Doctor compared his Molenski Univarius to a Swiss Army knife. (AUDIO: The Axis of Insanity)
The Thirteenth Doctor compared her sonic screwdriver to a "sonic Swiss Army knife", because of its versatility, but without the knife. (TV: The Woman Who Fell to Earth)
Liv Chenka called the Eighth Doctor a Swiss Army knife of sciences. (AUDIO: Scenes From Her Life)