Depends on what you want to do then.
If you want to edit more than one at a time, use QT Script Editor.
If you want to run several Scripts:
1. Every Script must be configured to make in openable by another script.
(Edit -> Action -> Action Properties -> Check: Reuseable Action)
2. Create a new script
3. Generate the Statement to Call the Script you want to run, for every Script.
(Insert -> Call to Existing Action)
4. Run the new Script, now all called Scripts will run after one another.
Edit:
The tabs you mention can open for example a Function Library at the same time, when a script is open, but not 2 scripts at a time
If you want to edit more than one at a time, use QT Script Editor.
If you want to run several Scripts:
1. Every Script must be configured to make in openable by another script.
(Edit -> Action -> Action Properties -> Check: Reuseable Action)
2. Create a new script
3. Generate the Statement to Call the Script you want to run, for every Script.
(Insert -> Call to Existing Action)
4. Run the new Script, now all called Scripts will run after one another.
Edit:
The tabs you mention can open for example a Function Library at the same time, when a script is open, but not 2 scripts at a time