Some Ubuntu 13.04 applications cannot access files on MTP-mounted systems. Why?
Solution 1:
The MTP specification doesn't support the basic open/read/write/close operations that are required to implement normal file access on Linux - it only provides upload/download for files, and that's what the MTP backend implements.
Nautilus will copy files just fine, but as soon as you try to use an application that doesn't explicitly account for the restricted set of operations, you'll get an error. evince is an example of an app that does support it (it copies the file to /tmp then opens it).
So, that's what's going on in 13.04.
Now, it happens to be the case that Google implemented a set of MTP extensions in Android that offer open/read/write/close, and it's possible to provide normal file access with these. I've done this work in the gvfs development branch but it missed the 1.16 release window, so it's not going to show up in Ubuntu until 13.10 at the earliest. 14.04 and still not there
In the meantime, you can use my ppa to install builds where I have backported this work.
https://launchpad.net/~langdalepl/+archive/gvfs-mtp
Finally, it's important to note that these extensions only exist in Google's MTP stack. You have a Nexus 10, so it will work as it's running stock Android - but someone using a Samsung device, or devices from other manufacturers, will not have these extensions and might not have support for normal file I/O.