Tablesome comes with so many options to customize the table but if you want more customization you could add custom CSS to modify specific tables.
Tablesome in itself does not have options to add CSS. But you can use other options with WordPress to insert the CSS code.
You can use this CSS for specific tables:
You have add it in the Theme Customizer or use a Code Snippet plugin to add the CSS. See this article for detailed information – https://www.wpbeginner.com/plugins/how-to-easily-add-custom-css-to-your-wordpress-site/