What is this History menu option in the menu bar and how do I clear it? Between the menu options Edit and View and sometimes between View and Go appears, when you open a web browser, another menu option named History that show all the recent browsing history.

How do I clear it when it appears? How do I delete the items that appear or, even better, only a selection of them?
I presume you are referring to Safari. The option appears when Safari is the front application.



You can clear Safari's history by going to History → Clear History….



To clear a certain section of history rather than the entire history, press ⌥⌘2, select the rows you wish to delete and press ⌫.