The easiest way to obtain Tablicious is by using Octave’s pkg package manager.
To install the development prerelease of Tablicious, run this in Octave:
pkg install https://github.com/apjanke/octave-tablicious/releases/download/v0.4.3/tablicious-0.4.3.tar.gz
(Check the releases page at https://github.com/apjanke/octave-tablicious/releases to find out what the actual latest release number is.)
For development, you can obtain the source code for Tablicious from the project repo on GitHub at https://github.com/apjanke/octave-tablicious. Make a local clone of the repo. Then add the inst directory in the repo to your Octave path.