However, based on the filename, this looks like it might be a , a data export , or a list of Steam ID codes (since "306" followed by an 'x' often appears in hexadecimal or specific database strings).
If you can (or a summary of what's inside), I'd be happy to analyze the data and write an essay for you. 306x Steam.txt.txt
I don't have access to your local files, so I can't read "306x Steam.txt.txt" directly. However, based on the filename, this looks like