On the Activity page, as well as exporting a range of transactions to a CSV, it is also possible to export individual transactions to either CSV (for editing) or PDF (presenting the information in read-only format).
Find the transaction you want to export, click 'Open' and from here, you can either click the 'Export' text to directly export a CSV file, or, click the drop-down icon to present both the CSV and PDF options as shown below.

