I have never heard of esoteric folklore so I would assume that
is the folklore surrounding esotericism. The reason I have
reservations about this is because esoteric practices were
secretive by nature and therefore wouldn't accumulate folk beliefs
and stories. Just to clarify esotericism was or is a term
associated with and used to describe philosophies that couldn't be
understood by man or a broad term encompassing mysticism, alchemy,
astrology, gnosis, occult and ritual magic.