I’m having difficulty opening large CSVs that I’ve downloaded?

You may wish to try one of the following CSV viewer tools:

• http://delimitware.com/  (there's a free-trial version)​
• Open office has an Excel-like tool called 'Calc' https://www.openoffice.org/download/
• UltraEdit It won't display the CSV in 'tabular' fashion, but it should allow you to search for the OwnerID, and then copy and paste the record to a separate file.
• Notepad++