How Do I Get Many Text Boxes Which Are Associated with One Item, on a Single Line?

Upon cloning the form in question I noticed that the Full Name tool is being used for the order fields. Now, while it's true that shrinking the width of each of those fields (please see this guide) would get them aligned in the manner illustrated in your image (somewhat), our Infinite List widget would be more suitable, especially since you want users to be able to add additional fields. Please give it a try and let us know if it's to your liking.

Thanks