in the upper left you see an arrow pointing to the right. click there you can create another tab.
it makes sense to create a tab for a class or function you wrote.

for example when using controlP5 to create a GUI you have to make a lot of calls in setup.
instead of writing them in setup you can create a function called initGUI() for example and then just call initGUI();
in setup.

hope it makes sense.

so i dont need to import the new tab?

not sure what you mean by import tabs but no,
when created once like mentioned above, you can easily open one of the pde files in your sketch folder and it opens all the corresponding tabs.

ok thanks!