Filter assets added to sharedassets0 ?

Hi, i noticed that when i build my game Unity seems to add assets i don't want/need to the sharedassets0.assets file, from my understanding it is only meant to 'store' dependencies assets.

In my /Assets/ folder i have an "Avatars" folder with characters and stuff that i package individually as assetBundles, so i don't need them in my app data.

If i build my game with the "/Assets/Avatars" folder in my project, the sharedassets0.assets is 108Mo. If i remove the "/Assets/Avatars" from my project the sharedassets0.assets is 42Mo

The scene i'm building has no reference to the assets under the "/Assets/Avatars". Why would unity still add them to the sharedassets0.assets file ?

I have no Ressources folder either in that structure. The structure is as follow:

• /Assets
  • /Avatars
    • /xxxx

      • /materials

      • /prefabs

      • /resources

      • /textures

What am i doing wrong, and how can i fix this ?

Thanks a lot !