LibreOffice Calc file size increase after duplicate filter

[bob.bobby]

Hello,
I am exporting a contact list from Quickbooks into a CSV file. My contacts has repeat entries, and I’m using Calc to eliminate the duplicates. I am following the directions on this page:

https://help.libreoffice.org/latest/ro/text/scalc/guide/remove_duplicates.html

My question is related to filesize. My original file exported from Quickbooks is 56KB. When I filter out the duplicates, the filesize becomes 8MB, although the duplicates have been removed. Can anyone help me, where I went wrong? Thank you much

[Zizi64]

Please upload sample files here (“before”, and “after” state).
Use dummy data instead of the real contact list.