Here is a blog post exploring the mystery and utility of these types of files. 857K.txt: The Mystery Behind the Digital Placeholder
used for security testing or spell-checkers. Extensive data exports from a database or spreadsheet. Why Do These Files Appear? 857K.txt
To put it in perspective, a standard novel is about 500K to 1MB. This means an "857K.txt" file likely contains: or script logs. Here is a blog post exploring the mystery