This module will add a new component to Webform module that allows you to render multiple components inside a table element.
Be advised this module isn't compatible with multi page webforms, if you want something similar have a look at Webform Ajax Page.
In this module there is a submodule that provides integration with Form Builder. We recommend using the latest dev version of Form Builder. Only not working is the preview, but after hitting save, preview is fine, see #1292668: How to handle complex components
For Webform 4, use the 4.x branch of Webform Table Element, for older versions of Webform, use the 1.x branch.