Summarize:

On some Samsung Galaxy tablets, you can enable a setting which allows you to take a screenshot by swiping the edge of your hand from right to left across the screen. This feature isn't available on every Samsung tablet, and you can't use it when your tablet's on-screen keyboard is displaying. This will prompt the Notifications drop-down menu to appear. It's in the top-right corner of the drop-down menu. Doing so opens the Settings app. This is on the left side of the screen. The Advanced Features menu will open on the right side of the screen. It's on the right side of the screen. The switch should turn blue, signifying that you'll be able to use a palm swipe to take a screenshot from now on.  If this switch is blue, the "Palm swipe to capture" feature is already enabled. If you can't find the "Palm swipe to capture" option, your Samsung tablet can't use this feature to take screenshots. Try using your tablet's buttons instead. Open the app, screen, or page on which you want to take a screenshot. The "Palm swipe to capture" feature will only work if your tablet's on-screen keyboard isn't active. You can get rid of the keyboard by tapping on a non-text field somewhere on the page. You can use either hand, but you must place the pinky finger edge of your hand on the far-right side of the screen. Doing so will cause your tablet to take a screenshot; you'll know a screenshot has been taken when the screen zooms out slightly. Your tablet may also vibrate or make a confirmation chime. Once you've taken your screenshot, you can open it in one of the following ways:   Notifications menu — Swipe down from the top of the screen, then tap the Screenshot captured notification.  Gallery — Open the Gallery photos app, tap the ALBUMS tab, tap the Screenshots album, and tap your screenshot.
Understand when to use this method. Swipe down from the top of the screen. Tap the Settings  icon. Tap Advanced features. Tap the white "Palm swipe to capture" switch . Go to the item you want to screenshot. Make sure that your keyboard isn't showing. Place the edge of one of your hands on the right side of the screen. Swipe your hand left at an even speed. View the screenshot.