Set rotation tool to local rotation, rather than center of last selection, option?

I bumped another thread that was similar but not exactly the same as this issue.

I want to select multiple static mesh actors in a level and rotate them all individually at the same time using the rotation manipulator. Currently it just rotates them as one big group, around the pivot of the last selected actor.

Here is an example video:


What is the meaning of the word “bump or bumping” I’m not a native speaker and I usually see that word. Can somebody help me?