The steps are in my reply above, which shows how to resize the Styles field (that turns into the tabs you see, when you close Customize mode and return to normal).
Did you try the steps and run into a problem? What goes wrong?
Apologies if I am missing something but you seem to have asked the same question that was already answered. If there's a problem with the answer, please give details and we can help.
I was not precise, sorry. Your first answer related to two computers:
On one computer, I could see all 8 tabs (Dual Horizontal …Metadata)
On another computer, I could see only 3 tabs. With your answer I can now see all 8 tabs.
On my third computer, I can only see “File, Edit, Tool, Settings”. I cannot see any of the 8 tabs right of “Settings”. What should I do to see the 8 tabs?