Each time you click the Field button, the Field screen is "recalibrated" depending on the current form, the cursor's position in it, and the currently selected text. So that extra moment is required to be sure you are only provided with valid options -- without it, scrambled forms would be the result. But two shortcuts can speed up the process a bit:
1. After adding a field to a form, you're welcome to copy it and paste it anywhere else it's needed, rather than create it from scratch each time.
2. If you're more of a keyboarder than a mouser, use the quick keystroke shortcut Alt+Q, Q open the Field screen.
Originally submitted by Scott Campbell