Yes, absolutely! You can download your entire archive of articles that's in your Authory account anytime. Please note that this doesn't work from mobile devices, only desktop computers.
Simply log in to your Authory account and click "Account Settings" in the sidebar menu. There you'll find a dropdown labelled "Download all your articles as one HTML per file". Alternatively, you can also download all your articles as one XML file.
You can also download a PDF of every article in your account. Simply go to the respective article page in your account, and then click the "more" icon next to the edit button. A dropdown menu will open with the option "Download PDF":