beventpack files are SARC archives that contain event files.
The Actor directory contains files defining the actor objects that populate the game world (e.g. enemies, buildings, NPCs). It also includes configuration files for the actor and AI system.
In particular, event packs sometimes contain bas files in Actor/AS.
Camera contains camera animation files for in-game demos (cutscenes).
Demo contains configuration files for in-game demos (cutscenes).
If the DLC is installed, this directory can be found in the unpacked content files in the add-on content directory. Its canonical path is "Sound".