Access to Wifi External Hard Drive

At home to preserve memory and backup things, I keep a Toshiba 3TB external drive attached to my router. I access it through my PCs and backup photos/docs/music/whatever to it from every PC.

My wife and I are both amateur photographers, and tend to gather lots of photos so it only seems fitting to store them for backup.

With that being said, I was wondering if there is a way to access that drive from my phone? I have also been considering purchasing a Samsung 10.1 tablet and wondered if I could do the same from there?

If it can be done, can you walk me through how to access it?