Symbols

Inserting

(Insert > Symbol)
(Insert tab, Symbols group)

Closing the Dialog Automatically

The dialog box is not automatically closed if you double click a symbol.
The dialog box is not automatically closed when you press the Insert button.
Replacing the built-in command with the following will mean that the dialog box is closed automatically

Public Sub InsertSymbol() 
   Dialogs(wdDialogInsertSymbol).Show 
End Sub