Hey Howdy Hey Rachel and welcome to planDisney!
I love that you are thinking about requesting a particular seat for your
advanced dining reservation to see the epic nighttime show in
EPCOT Harmonious! This show is absolutely spectacular and is one of the top "Must Do's" in EPCOT. Now there are a lot of things you can request on your reservation, but as you found out, table requests are not one of them. Let's talk about how to try and get the best seat for the viewing of Harmonious.
To have a specific table request for your advanced dining reservations, this would have to be done in person when you check-in for your reservation that day. When you talk to the greeting Cast Member at the host stand, let them know your preferences for the table request. They will try hard to make the request happen, just know you might have to wait a little longer for your reservation to give them time to have this done. Checking in early might also help to get the ball rolling a little earlier as well.
Another option you have to guarantee that you will have a great spot for Harmonious is booking a
dining fireworks package. There are two in EPCOT to choose from
Spice Road Table Fireworks Dining Package and
Rose & Crown Fireworks Dining Package. With these reservations, not only would you get a fantastic meal but you would also get a great spot to view the nighttime show without the hassle or stress.
Good luck getting all of the dining reservations you are planning for and I hope you are having a fun time planning your Magical holiday. We cannot wait to welcome you to the Most Magical Place on Earth real soon! Let us know if you have any further questions, we would be happy to help.
Happy Planning,
Nick