Conjuring Things Out of Thin Air

[Cindy C.]

No: HPFGUIDX 28659

--- In HPforGrownups at y..., doseylel at a... wrote:
> 
> In the beginning of GoF, Bill and Charlie conjure tablecloths out 
of 
> thin air for the battling tables.  This is ,of course, after Percy 
> yelled at them for disturbing his work.  To which Bill replied 
(with 
> a very sexy grin) "Sorry, Perce."  That's one of my favorite 
scenes.  
> The chaotic big family get together.  Brings back memories!
> 

Drat!  I think that totally kills the theory that you can't conjure 
things for yourself (unless Bill skipped dinner).  There must be some 
rules in the wizarding world that deal with this, but I can't figure 
out what they are.

Can anyone figure this out, because I am totally stumped?

Cindy