https://www.cnet.com/news/samsung-galaxy-tab-s4-is-a-649-2-in-1-android-tablet-for-multitaskers/

Like Microsoft's Surface line and Apple's iPad Pro, this premium Android tablet is for more than entertainment. Borrowing capabilities from the DeX dock and pad Samsung makes for its Galaxy phones, the Tab S4 has DeX support that changes the tablet's Android interface into a desktop-style experience. 

Attach the $150 Book Cover keyboard (no, it's not included) and the interface changes, letting you run multiple apps side by side and resize their windows, and even drag-and-drop content between them. If you're thinking a 10.5-inch screen doesn't give you much room to do that sort of work, Samsung will offer an HDMI-to-USB-C multiport adapter for a secondary display (also not included).