Adding an Amplify Feed to a Facebook tab is pretty simple. You will have to install an app -- we prefer the "Static HTML Plus" app (https://apps.facebook.com/static_html_plus/), which is free and very simple to setup.
After you've installed the app, paste the code that you get from clicking "Publish -> On a website". Save & Publish. You are now good to go. Keep in mind however that Facebook tabs are not supported on mobile screens (it's crazy, we know).