IPad + Mac/PC app that will share thumbnails

IPad + Mac/PC app that will share thumbnails

I am looking for an app that can be run on Mac/PC(Win, Linux) able to
generate thumbnails that then can be used on IPad - any ideas? In general
I would be happy with FileBrowser if it only could recognize thumbnails.
I have around 100GB of pictures (stored on NAS) and I would like to view
them on my IPad and I have 2 problems with it: a) viewing single image
takes few seconds because of file size b) generating thumbnails from IPad
is very cumbersome task with such a big collection
Thanks.