Tom lights a candle before he goes through the door. The same door Goldberry entered from? It seems so.
The wording here confuses me, because it's "the" door, but Tom returns quickly with a laden tray. This to me suggests that he went to the kitchen, and not out the front door.
Before Tom goes out he dances around the table, and we also have this passage later: "Yet in some fashion they seemed to weave a single dance, neither hindering the other,
in and out of the room, and round about the table; and with great speed food and vessels and lights were set in order."
To me this suggests that Tom and Goldberry are dancing around the table and going back and forth to the kitchen, which is what Tom did the first time to get the tray.
Anyway, we know that there are multiple doors off the main room, and maybe Tolkien was just a bit imprecise with his wording.
Is Tolkien referring to the aura that the candle puts up in front of and around Goldberry?
That's a very interesting interpretation. Is she framed, in the sense that she has a glow around the outside of her body? That's kind of what I was suggesting above with the light "pervading" her.
Just as the candle is a source of light "like sunlight through a white shell", is Goldberry herself glowing with light? If this is the case, it's hard not to notice possible religious connections.