That is abnormal.
With those timing settings, it takes about half a second to type "This is a test" into Notepad on my machine, as shown (you may need to click the attachment for the animation to work).
Though, in the context of sending input to an application, typing is out would be one of the most inefficient methods.
You could use an inline function and utilize one of the many available inter-process communication methods available in .NET, instead.
If it absolutely needs to be passed into a text input field, pasting by using the "Set a Text Value to the Windows Clipboard" action and a keypress action that presses and releases Ctrl-V (or Shift-Insert) would be much quicker than typing, even at normal speeds.