Moved 2nd part of first name to middle name

[enjoy2020]

Hi guys,

When I immigrated to Canada, my first name was having 2 parts and middle name was left blank. However last year, I got my SIN updated, and moved the second part of my first name to the middle name. My question is:
Do I need to mention it as a separate name I used in a separate row in question: 5 or do I just explain it in a separate letter?
I have this query because the second row in the table asks for: Given Name (First name).

Please suggest.

Thanks

 

[enjoy2020]

Hello Seniors, please help with your valuable suggestions.