Setting the Stretch Text checkbox enables the Stretch Text button.

Enter the data you wish to display across the multiple cells in the Data to Display field.

In the demo I have

CLIP(BAP:Contact) & ' ' & BAP:Notes

Pushing the button "Set Prompts For Stretch"  prepares the existing settings in your template for using the new display.  It tells you in the box what will be changed.

You can easily return to older settings by unchecking the Stretch Text box, and resetting your icons, Justification, Right border, moveable border to earlier settings.

BizDay booking template with StretchText enabled.