Within the help for the file column, it states that all files can be downloaded as indicated below from the Gallery View:
“When you click on a file, you can select ‘Download’ to download a single file, or ‘Download all’ to download all the files in the group into one zip file!”
However, in my column of PDF and DOCX files, I do not get a Gallery View in the summary, thus I cannot download all files–I can only open one file at a time from the list.