Articles are the small modular content inside the CMS content workflow, the Browser Page Title is managed by the structure of the Menú and the last part of this process comes from the direct assignment of the article title... by default.
In the tab "Publishing" we have another options like Meta's, related to SEO, now, the option for add custom Browser Page Title can be related to that too, that's why I think that this have more sense for you in this case.
We can say that we have this "extra" option in articles for more advanced or specific needs, an option to customize this for each one, thats why is under "Options" Tab, because is an option.
You are in the correct table:
- Inside the xxxx_content table (xxxx is of course your db prefix)
- Find your article and click to Edit
- Here you can find a column called "attribs"
- Edit the value for "article_page_title":"Your custom Browser Page Title"