You can just use sqlite then. Very compact, highly popular (in different role though). Seen it used for large datasets - map tiles (millions of jpeg files). Much smaller size than zip or tar archive, indexed, fast.
> This results in a truly hierarchical, filesystem-like data format. In fact, resources in an HDF5 file can be accessed using the POSIX-like syntax /path/to/resource.
That seems a whole higher level of complexity compared to CSV or the other options listed in TFA (perhaps comparable to Excel).
NetCDF4 (built on top of HDF5 largely through sub-setting) is considerably more powerful than excel/libreoffice. Its also easy to access through widely-available libraries. I frequently use the Python `netCDF4` (yes, it really is capitalized that way) library for exploratory work.
Its a little weird at first but its a great format and has libraries in a lot of major languages. It stores a sparse matrix which cuts the size down a lot.
https://en.wikipedia.org/wiki/Hierarchical_Data_Format