Yup, It's a plate camera from early last century. There are lots of them out there (I have three, and I wasn't even trying to collect them!) The plate holder you show doesn't seem to have the film insert - was there more? Do you have the ground glass back as well? If not, it may be possible to pick these things up; they often get orphaned. You don't indiocate the size of the camera or the focal length of the lens. It's most likely a 6.5 x 9 or a 6 x 9 (close to 2.5x3.5) or a 9x12. Film is available for either size and there are roll film backs that fit.
Now for the bad news: there are lots of different size/style backs, and you have to get the ones that fit. If Ole chimes in on this thread, he can tell you just about anything you want to know about this kind of camera -- he's been educating me for the past year or so. And check the plate camera sub-forum for threads like this one. You can pick up quite a bit through other people's questions.