The user can instill and infuse vast amounts of knowledge into their mind by various means (supernatural, technological, etc.), rather than acquiring it through normal means such as study, experience, etc. The knowledge can be of any and all kinds, natural, supernatural, the known, the unknown, etc. One with this ability may have instilled knowledge in a specific field of study (like math, literature or a branch of science) or all subjects. The user may even have knowledge about the past, present or future, about alternate realities, the minds of others and knowledge beyond normal comprehension.
Thanks to Wolfram & Hart's legal upgrade, Charles Gunn (Angel) was instilled with knowledge of all human and demon laws, some demonic languages, golf techniques, and all Gilbert & Sullivan compositions.
Xander Harris (Buffy the Vampire Slayer) gained extensive knowledge of military protocol and weapon handling after being magically transformed into a soldier.
Edison (Wansapanataym Episode: 147) after being massaged by Benson on his brain, gained Enhanced Memory, Enhanced Intelligence and Intuitive Aptitude and later gains Telepathy, Mind Reading, Voice Projection and Adoptive Muscle Memory.
The "redpills" (The Matrix) can have all manner of knowledge, such as martial arts skills and how to operate vehicles, uploaded directly into their brains via their headjacks.
As a result of extensive hypnotherapy, Venom Snake (Metal Gear Solid V: The Phantom Pain) has obtained knowledge of combat experience and skills equal to those of Big Boss.
Prometheus (DC) is able to download the skills and abilities of anyone he has on record, as well as any knowledge he requires, through his helmet.
SCP-028 - Knowledge (SCP Foundation) can instill absolutely any form of knowledge into a persons mind when they enter its area of effect, the knowledge can be practical, supernatural, mechanical, or anything else. What knowledge attained is completely random.
Tohsaka Rin (TYPE-MOON) is able to instantly download the skills and knowledge of parallel versions of herself by transforming with the Kaleidostick Ruby.
Trinity (the Matrix) downloads knowledge to fly a specific model of helicopter
Fountain of Hui (Xiaolin Showdown) gives unlimited but random knowledge, which overloads the user. Combined with it's sister Shen Gong Wu, The Eagle Scope, it can unlock the greatest secrets of the world.