Patrons should have settings to designate which titles should be saved in the circulation history by format and language (and possibly other options) and how long they want to retain the titles in the list -- for example, a patron may want to only save books and not DVDs and other formats, automatically remove titles checked out more than two years ago, etc.
Patrons should be able to search, filter and sort checkout history display. Filter options should include format, language and when the title was checked out. Sort options should include author, title, date of publication and all other columns shown in the display
Patrons should have a way to apply a star or other designation to selected titles, to make it easier to find them for whatever reason. This would be similar to the use of stars in Gmail, Google Drive, etc.
Patrons should be able to select titles and apply actions to those titles. Actions should include (but not be limited to) download, delete, add to a new list, add to an existing list and download CSV.
The option to download CSV should include a filter so patrons can only download books checked out in the last year, or only books in Spanish, etc.
ISBN should be included in the CSV output options, which would make it easy for patrons to connect with Google Books, GoodReads, the Diverse Bookfinder's Collection Analysis Tool and other services that work with files of ISBNs
+1 The list gets very unwieldy very fast as it is.