You can display a publication or a library widget in a dedicated tab of your Facebook page by adding an iframe tab.
Go to this page and click on Add Static HTML to a Page:
Select the page you wish to add your publications to and click Add Page Tab:
Once in your new tab, click on Set up tab:
Copy your publication’s embed code or your Calaméo library widget code and paste it here:
You can Preview your iframe, and customise the embed code to change the size etc., if you wish. Finally, hit the Save & Publish button.