I have talked about the Álfablót already, but there was much knowledge left to be told and the lore is wide, so i will try to write it as simple as it can be.
The Norse/Germanic peoples were always surrounded by entities of great power all over the land, were those gods or goddesses, landspirits/landvaettir, Alfar (Elves), Dwarves, ancestors, Trolls, Huldrefolk and so on. Every entitie lived in the land, on trees, rocks, streams, in animals etc. and helped the people in their daily needs, mundane life, they would also help giving guidance and wisdom, or for some, in their magical works. The people lived in close association with these spiritual entities, and the connections and friendship between the two sides, was forged through a series of ritual actions. The most important ritual or celebration in this matter, was the Álfablót, which was performed at the Autumnal Equinox.
Such as the Disablót, the Álfablót is also a celebration that was held during autumn a bit before or during the Winternights/Vinternatsblót by the Norse/Germanic peoples, and the aim of this feast was to help the participants connecting with the nature spirits in their area and to begin to establish the relationship of mutual trust, respect, and support with them.
Unlike the other blóts, this one was a local celebration at the farms and homesteads of each family and no strangers were allowed near the place during these times, this is because the Elves are in close connection with the ancestors, and so Álfablót was of great importance for each family, because of their particular affections and love that people felt for the family members that were already dead. Obviously, we can assume to know why strangers weren’t welcomed and why this celebration was a local family thing, because those that did not belong to the family and did not know those that used to belong to it, can’t possible understand the feelings shared by each family member, and strangers should be at their own homes with their own families, unless of course, people were bonded to each other by marriage and thus, they would become a family member also.
This celebration is still held today in many places, and today you can invite whoever you want, because the main objective of this feast, is to be connected with the spirits of the land. For instance, in Iceland, people still honor the local spirits of the place were they live, or ask them if they can build their home in specific regions, because the human presence may not be welcomed at such places by the spirits of the land.