@Obi-wan – yes. If we have a Source document and one or several Target documents open (or available) we can establish a connection with unique labeled cells in Source to various target cells in the Target documents. Changing the contents of the Source would not affect the labels. Unless we build a totally different target table. What I have to check is, if updating a table with a linked Excel file will only "update" the contents of the table or rebuild it anew (and that would erase all already assigned labels).
Uwe