A New Moon Question...

In the first chapter of New Moon when Bella enters the house for her birthday Stephanie writes,

There was a table with a white cloth draped over it next to Edward's grand piano, holding a pink birthday cake, more roses, a stack of glass plates, and a small pile of silver-wrapped presents.

I was just wondering why there would be stack of glass plates when Bella would be the only one eating the cake (even though she probably wouldn't because she would be "celebrating her birthday")?

The only reasoning I could come up for this is because Alice always goes all out for her parties.

And just one random fun question...

The Cullen's use other aliases for credit cards and what not. What do you think these other names for each family member would be?

I think you are right, Alice always goes all out, and I think she wanted to make it look more "normal".