Oh right. I think I understand what you are trying to do.
Anytime you create a page it appears in the top tabs.
The best navigation tool I use is NAVT
It’s a brilliant tool and will allow you much greater control over your page navigation.
Upload and activate the plugin.
Go to Manage > NAVT Lists
In here you can create a new navigation menu, say call it “main”. Once it’s created you can drag any of your desired tabs from “unassigned” to “main”
Then, go into (I’m guessing here) your header.php file and find the wp_list_pages() function and replace it with:
<?php navt_getlist(main, $bEcho=true, $sTitle='', $sBefore='ul', $sAfter='/ul', $sBeforeItem='li', $sAfterItem='/li') ?>
This code will tell your theme to render that main list of navigation items.
It might require a bit of work in around that, but it’s so worthwhile as you can create more menus and use them as widgets in your side bar.
Otherwise, if you don’t like the sounds of that, and assuming your template is using wp_list_pages to create your tabs, then have a detailed read of:
https://codex.www.ads-software.com/Template_Tags/wp_list_pages
Everything you need is in there (just not quite as cool as NAVT)!