I'm using PL/SQL Developer Version 15.0.4.2064 (32 bit)

I have a table with a CLOB column.
When I paste text containing TABS characters, the pasted text has two spaces instead of the tab character.
In other words, each TAB character (ASCII #9) is converted to two spaces (ASCII 32).

Try this example:
- open a new file in a text editor, like Notepad++, and write the text:
1234[tab]5678
([tab] = the tab character)
- copy the above text (nine characters)
- open PL/SQL Developer, edit a CLOB field using the Large Data Editor, Text mode
- paste
You will see 1234[space][space]5678
Double check with the Hex mode. You'll see 2020 instead of 09.

This is a serious issue (unless there's already an option to avoid it), because we need text to be placed exactly as it is.

Thank you.

Found the solution: in the Options -> User interface -> Editor:
- uncheck "Smart Tab"
AND
- check "Use tab character"