Akasha in Sanskrit philosophy means space, or the subtle element associated with sound and with the medium in which things exist. It does not mean a record. The idea that every event is inscribed on it, and that a suitably trained person can consult the inscription, is a Theosophical construction of the late nineteenth century, and the phrase akashic records is English rather than Sanskrit.
Blavatsky spoke of an indestructible tablet of the astral light. Leadbeater and Alice Bailey developed the reading practice around it. What turned it into a widely known idea was Edgar Cayce, who from the 1920s gave several thousand readings in a trance state, describing past lives, medical conditions and prophecy, and attributing his information to these records. The transcripts were kept and are archived, which makes them unusually checkable for material of this kind, and they are the reason the term is in general circulation.
The idea has an obvious appeal and an obvious problem. It offers a universal archive with no gaps and no custodian, which means no possible failure of access and therefore no way for a reading to be wrong. An atlas can record that the concept exists, where it came from, and who developed it. It cannot treat the archive as a source.