The stable versions of ViTables are available in its SourceForge page.
ViTables packages exist for several GNU/Linux distributions, although they aren't always up to date. Some of these distros are OpenSUSE, Mandriva, Arch Linux, Debian, Ubuntu, Gentoo, Trisquel and Fink. Just use the distro's package manager in order to find and install ViTables.
In addition, you can get the latest (and possibly buggiest ;-) sources from the git repository.
Last but not least, ViTables is included in a couple of scientific-oriented Python distributions, WinPython and Python(x,y) (which provides Windows binaries, in this page). Also you can get the Windows binaries (and many other binaries for interesting software) from Christoph Gohlke's website.