How can I creat this workspace in UV editor? I would like to create a similar workflow. I've downloaded a file from a popular free 3d Model website, so I noticed that I like the workflow, in the file, many objects, not matter the shaper they are, you can match the geometry in the UV place, notice that there are just rectangle with texture on it. I used to use texture paint and many tools in UV, even texture atlasing, but I would like to make this 4 funny stuff.
I'm not totally sure what you are asking, but, my best guess is that your the image shown is just one texture and the UV maps are just moved to cover one section of the texture. You can grab, resize, etc. within UV edit mode by just grabbing the points.