If you can’t reproduce it, you misunderstood it.
Try to mark SOME lines (blocks) by drawing a rectangle frame.
Then, no matter if you only hover the mouse over the selection or if you press the right mouse key - nothing happens.
The toolbar menu doesn’t appear.
The toolbar appears only if you select a part of a single block.
But if you have some textlines divided by pressing return, they become individual blocks.
And it is not possible to change for example their background color all together. You have to do it block for block.
Assume you have some lines like this:
Line 1
Line 2
Line 3
Line 4
– Try to convert that in a numbered list!
Or try to modify the background color of all four lines.
It’s cumbersome to modify each single line one after one.