Realistically you can create as many tabs as you can fit in a single row.
The only limit on how many Tabs you can have is the value of the responsive breakpoint in the CSS. This value can be changed if you use custom styles to replace the default styles (or by using the optional Tabby Responsive Tabs Customiser Add-on).
If the number of tabs, the amount of text in each tab, and the CSS styles applied to the tabs results in the row of tabs being longer than the width available to accomodate it, the tabs will wrap to a second line. Although some people do use the plugin like this, I don’t recommend it as the default styles are intended for a single row of tabs only.
Have you resolved your issue? If not please provide a link to the page where I can see the tabs.