Try conversation, which is the intent for such a thing. Just remember to start your conversation somewhere. ;)
If you need the data on that single page only and you are not even changing the data, then you can store the list in page scope.
If I am not mistaken you can do that in the getAllUsers() action handler, because writing to page scope in an action handler writes to the new page.
However I would probably rather add a page action for pageB that calls a method that retrieves the values.
That way the data will always be present no matter how you navigate to the page (plus the page could be bookmarked).