Hello,
An additional tab can be added globally: one for all the products (in the Theme Settings > Product page > Tabs > Additional tab and another tab can be added individually for each product on the product page. https://xtemos.com/docs/woodmart/options-for-pages/
You can add two tabs max. If you need more tab you can check the below documentation for this purpose: https://docs.woocommerce.com/document/editing-product-data-tabs/
The “About Brand” tab only display when you add brand attributes to some product. You can check the below documentation:
https://xtemos.com/docs/woodmart/faq-guides/how-to-setup-brands/
About the size guide if you want to make the same upper portion then simply edit your size guide with Wp-Bakery Page Builder from Dashboard >> Size Guides option and design your sidebar by creating two columns, in the very first column you have to use your image, and in the second column you have to use information box theme element with the help of Wp-Bakery Page builder.
Also you can check the below documentation for more guidance:
https://xtemos.com/docs/woodmart/faq-guides/create-size-guide-table/
Best Regards.
.
