Yes, but only over the bridge. It must float over a solid surface, however flimsy.
Assuming everyone is ready, Grigo will ferry them all across. The disk can travel 5 squares from Grigo, so for the last step they will have to tread lightly or jump. If anyone feels uncertain of their ability to do this, Grigo can also ride across with them; then it can go the whole distance. Once we are across, he will offer to let Eithal drop the nobleman's body on the disk to free up her arms for fighting. This disk will follow me around all day; feel free to pile baggage on it.