Is there PREPEND and MAP TO kind of action as opposed to APPEND and MAP TO in data transform?
I am appending a new page into a pagelist, using action append and map to, this appends each new page at the end of the pagelist on click of a button where I have called the data trasform. I have used key word LAST for each SET action in data transform. However, I need to PREPEND meaning, I need to insert each page as the first page of page list and older pages need to be pushed down each time I insert new page at index =1. This is to make sure the latest pages appear first.
Is there any work around or design consideration?

Yes, you can use <PREPEND> syntax as per this help topic.
Instead of doing "Append and Map to" in the Data Transform you would need to use a regular "Set" and enter the page list name.
For example:
One other thing to note from your post is that if you are using "Append and Map to" you do not need to use the <LAST> syntax when setting the properties as the Data Transform will understand that the context is the new (last) page.