Yeah, you have to deal with him when you are done with the main quest on Fort Joy. This content was available in early access, and you do meet him as a boss figure very early in the game. So not a big spoiler. I hope.
Elves can consume humanoid body parts to learn last thoughts and even deeper memories of the owner, sometimes learning a quest clue, lore bits and even Skills. Sometimes it's not an actual body part but a piece of meat, just right click it and see if it says "Eat" (for an elf), instead of consume. Just don't eat the rotten ones.
The very first body part can be found on the ship in the prologue - the murdered guy.
Also Pet Pal perk is a must for the full experience, imho. Animals can provide clues for your quests and some quests are only available from animals.