STR:
Open two new docs.
Move "New 2" to the other view.
Move "New 2" back to the other view.
Open a new doc.
Open another new doc.

Result:
Two docs titled "New 2".

Repeating those steps with more tabs, you can get:

Notepad++ v8.4.1 (64-bit)
Build time : May 20 2022 - 00:41:35
Path : C---Notepad++ Original.exe
Command Line : $COMMAND_LINE_PLACEHOLDER$
Admin mode : ON
Local Conf mode : ON
Cloud Config : OFF
OS Name : Windows 10 Pro (64-bit)
OS Version : 2009
OS Build : 19042.985
Current ANSI codepage : 1255
Plugins :
ComparePlus (1)
HTMLTag (1.2.3)
MenuIcons (1.2.5)
PythonScript (2)
_CustomizeToolbar (4.2)