Hello Paula.
I think, the only way you can accomplish that is this:
Go to your contributions list.
Select "show 500 per page".
Use your browser's search/find function (Chrome = ctrl + f) to look for the text "added Notables template".
This way, every line where you entered "added Notables template" in the "Explain your changes" field will be highlighted.
Do the same with the next 500, and so on.
I hope this may be of help.