A Fields & Tables Component consists of Fields and Tables. Unlike other Component types, it is not possible to add controls, resources, scripts etc.
This is a lightweight Component that is suited for situations where you want to use the same collection of fields and/or tables across multiple forms. For example, you might use the same set of address fields on multiple forms.
You can add a Fields & Tables Component to a form using the Add a Fields & Tables Component button
in the Fields or Tables tabs.