Adding Items From a File
It's possible to add items from a tab-separated file. This is done by opening the "Add items" dialog. This dialog can be opened from the context menu of the Instance Node or the context menu of the Module Node.
By selecting the desired item type, and clicking "File add", a dialog appears for selecting the file to use to create items.
The format of the file is specified here.
See Import Configuration for how to add items from multiple files at once.