As the documentation you linked states:
This read-only object contains all ContentDocument objects associated with an object.
For more information, see AttachedContentDocument in the Object Reference for Salesforce and Lightning Platform.
If you go there, it says:
Use this object to list all ContentDocument objects attached to an object via a feed post.
There's no way to do this without custom development. Data Loader targets exactly one object per data load.
You'd have to build a staging table and automation to transform it into a custom object + attachment, but that's a very bad idea because you'd dramatically limit the size of the attachment you can include due to governor limits.
Abandon the idea of one ...
Yes, those limits are globally applied. Note that some APIs will have a lower limit, such as a ContentVersion created by SOAP (which will be limited to about 37MB because of the 50MB payload limit), but using specified APIs, such as creating a ContentVersion using REST API with form/multipart will support 2GB file sizes.