This feat represents your knowledge of the Arcane. Characters with this feat are granted special quest-specific dialog options or object interactions that classes without it otherwise could not perform. It may also allow certain skill checks to learn insight into specific situations.
Verbatim from the release notes: Many classes now gain the "Arcane Lore", "Religious Lore", or "Wilderness Lore" feats every level, which may modify certain dialog options or come up in other ways during quests.
Known interactions
Rest Stop: One of the staves requires Arcane Lore in order to disable it safely.