Hello again, Doug.  I was wondering when someone would ask this, and have considered adding a "Delete" item to the File menu.  But for now, use the standard Macintosh document-deleting procedure.  This is one of those things that Apple assumes everyone knows, but actually few people know it.

1.  Open the document you don't want.
2.  Hold down the ⌘ key while clicking on the title of the window.  A popup menu showing the document's file path will appear.
3.  Click the immediate (first) parent in the list (probably "Bookmarkshelf Documents").
4.  A Finder window will open, showing the file.  Drag it to the trash or type ⌘delete.
5.  Close the Bookmarkshelf Document window, Don't Save.

This works in any normally-designed Macintosh document-based app.