Microsoft should look at this topic and then wonder why some people, including me, have no freaking clue what the actual topic menu in question is.
WHy is it called Info Center for me while it is called action center for you hilarious...
Had to google action center, and i use that on a daily haha.
BTW if Tablet mode is greyed out for you it might be due to multiple displays connected to your system.
To trick windows and activate it anyways is to enable surround on Nvidia cards or use the AMD Mutimedia eyefinity as far as i read in the web.
However i havent tried that myself since i dont have a touch Monitor myself.
Another way to use swipe is to hold both mouse buttons on your desktop and then move it to either side to switch to the second display.(if you have two or more attached)