Hi,
in video tutorials from epics was one with a trick how simply make 2 tabs fit whole screen, one tab on the left and another on the right, but now i can’t find that video and doesn’t remember how do it. If you know how or what video was it - tell me please.
Found in material, ty Zack again 
The trick is:
activate window you need and hold 'windows" key and press arrow key
If you still don’t got what am i talking about, just look at this part of the video Intro to Materials: Dynamic Material Instances cont. | 10 | v4.0 Tutorial Series | Unreal Engine - YouTube
Normaly you can just drag a window to the left or right side of your screen and Windows will place it to the left or right half of the screen.