Question about "Base Content Pack" update

At the top of my LIBRARY is a component called BASE CONTENT PACK. This showed to be an UPDATE. I clicked on it and it was about 167GB.. It took a while to download, now says READY to INSTALL. I am confused. What is this large? I stream the program thru STEAM. Is this the actual program that is now downloaded, so you don’t have to STREAM it? I have been using this since it was introduced almost 2 years ago. Not sure what I am seeing here.

You can expand it and see what it contains. It’s basically all the static aircraft models, boats, animals, challenges, etc.

The 167GB is the size of the entire Base Content Pack, not the size of the update. You can select “Update available”

and the size will change to show the actual update size.

As for streaming, it streams the content that you don’t have installed locally.