How To Increase Size

Do you mean the Category tabs?

Try adding the following CSS overrides in the wootabbed settings area:

.wtcpl_category_nav li a:link, .wtcpl_category_nav li a:visited, .wtcpl_category_nav li a:active {
    font-size: 18px !important;
}

.wtcpl_category_nav li {
    min-width: 190px !important;
}

You can change the values as needed.

Thanks

You are most welcome!
When you have a moment please consider leaving the plugin a geat rating. I will appreciate that. You can do that from here:
https://ww.wp.xz.cn/support/plugin/woo-tabbed-category-product-listing/reviews/#new-post

Thank you!