Thumbnail view of local network .pdf files on iPad?

Problem: I have about 250+ Lego Building Instructions saved on my MacPro. My kids like to rebuild the sets and I'm looking for a way to view these form our iPads WITHOUT me having to sync them.

Is there any app that offers a visual/thumbnail view of local network pdf files?

I'm aware that I could upload them all to Dropbox, but even then I was not able to find a visual view in the Dropbox app. And, since there is no need to go up to a cloud I'd like to avoid that step.

I would rather not have them even kept on the iPads but rather just have the iPads view the copy from my hard drive and then trash it on close off said magical app.

Any suggestions?