We do plan on adding a variety of features that will help specifically with non-fiction books, and we're looking into the possibility of supporting tables, but creating a system that generates tables compatible with both ePubs and PDFs is quite complex, so we don't have a definite plan as of yet.
In the meantime, the best workaround would be to create these elements as images outside of Atticus (using something like Book Brush or Canva is a great option), and then insert those images into your book where needed.