The TMFMHelp Popup Text Editor opens when you click either the Help Text elipses (…) on the Properties tab of the Object Inspector, or when you double-click the TMFMHelp component, after you have dropped it on your form.
Note: This is probably the window you will access most while using this component.
The HelpText property is modified via the TMFMHelp Popup Help Editor, a custom Property Editor that displays the names of each of the other controls on the form. As you select each control in the top list-box you can type the text and context-id in the two controls at the bottom of the page.