The tool can be accessed through menu / Tools / Transfer project notes to text.
This tool does only one thing. It copies the project notes into the currently opened project.
It does that by going through each verse of the project that is now opened in the editor. At each verse it looks at which project notes would display if that verse were visible in the editor. It then copies the text of those notes into the text of the project. It the text of a note is copied into the project, it does not overwrite the data that is already in the project, but it just appends it.
This tool can be useful in cases that somebody wishes to have some way of printing a subset of project notes along with the text, so that checking questions could be printed on the same page as the verses they refer to. To do this, the notes can be imported in some temporal project, and then a "Parallel Bible" could be created that includes that temporal project that now contains the notes.