help me find out this gift! riddle?

[Rosemary]

well, for a gift, my grandparents bought me something & they wont tell me.
it is bigger than a dog, smaller than a car
it is white
you can not buy it or sell once you see it
it does not run on batteries, fuel, etc.
it can fit in a box, & once you spend the gift out, it will be as big as a kitchen counter.
HELP!

 

[william]

I don't know, but you have to tell me the answer when you find out.

 

[JBere]

Sounds like a tablecloth.