It is a pretty simple thing to add an Amplify feed to a Facebook tab. You will have to install an app, we do 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).