The Divi Builder allows you to have up to four columns for page layouts. And, for most websites, four columns is all you need. But sometimes you need to add more columns. Of course, there are plugins that allow you to embed shortcodes to add extra columns to your layout. But, this can be limiting when working with the Divi Builder since shortcodes require that you work from within a module.

Read more: https://www.elegantthemes.com/blog/divi-resources/add-more-columns-to-your-divi-builder-posts-or-pages