Hi,

You can create a scheduled job that will read your file and based file data it will create the categories in the Episerver CMS

Example for creating a scheduled job-

https://blog.tech-fellow.net/2020/12/07/episerver-scheduled-jobs-under-the-hood/

Sample code to create categories-

private void CreateIfNotExists(string name, string description, int order)
        {
            if (string.IsNullOrEmpty(name))
            {
                throw new ArgumentNullException("name");
            }
            if (string.IsNullOrEmpty(description))
            {
                throw new ArgumentNullException("description");
            }

            var categories = CategoryList.LoadCategories();
            if (categories.Contains(name))
            {
                return;
            }

            var category = new Category(name, description)
                           {
                                   Available = true,
                                   Parent = Category.GetRoot(),
                                   SortOrder = order
                           };

            category.Save();
        }

FYI - If you have a multilingual site then you can use Geta Categories

https://github.com/Geta/EpiCategories