[Bermudagirl]

I use Calibre to manage all my books in Marvin on my iPad. Apart from the problem with cover art not displaying properly (something which I rectify by reconverting the epub in Calibre) - I really love the app.
Just one little query. I have just realised that I have way too many books on my iPad, and I want to remove a whole lot of them and just keep the books I really want to read on my iPad. I have been deleting the books through Calibre because although I want to remove the books from my iPad, I want to keep them in Calibre.
It's a slow process doing this. If I delete the books through Marvin on my iPad (which I am hoping will be a quicker process), will this affect the books I have in Calibre when I connect my iPad to Calibre on my computer?
This may seem a silly question, but I don't want to loose any of the books in Calibre (I have a lot of them) and I really don't want to have to put them back into Calibre, which would take ages.
Any advice would be much appreciated!