Perhaps, at the end of the paragraph here:
"This tool allows you to download one month of your journal at a time, and save it in either CSV (comma separated values) or XML (extensible markup language) format. While these formats are useful for archiving your entries, they are not designed to be easily readable by humans. You will need to save the file within your web browser and then open it with a third-party program. Many spreadsheet and database programs can read CSV files, for example."
I don't know what would be the best wording. I propose something like:
"XML files may be rendered readable in a browser with some editing."