How do you confidently take a seat at the table when you're the most junior person on your team?

Contribute and add value. The great part of recognizing that you are more junior is that you are likely very humble and are willing to put in the hard work to learn as much as you can and figure out how you can best be an asset to your team. On the otherhand, there are ample examples of "junior" people having significant impact. Elaine Welteroth of Teen Vogue was 29 before she became editor. Mo from Mo's Bows (shark tank) is 15 and has sold over $200k in product. Who is making your "junior-ness" an issue? You or your team? A good remedy and either case is to contribute effectively and make sure that you are doing what it takes to add value to your team! This can definitely help build your confidence too!