Done. I decided not to use xarray or pytables. Instead, I used H5Py.
xarray has no direct connection with HDF5. Using xarray would not have provided a simple path to HDF5 export for multidimensional reports.
I wanted to avoid a Python-specific implementation (PyTables relies on pickle).
I wanted a method that encodes metadata into HDF5 in a relatively simple way (PyTables adds more features, but these features make it that much harder to utilize HDF5 files produced by PyTables in other programming languages).
Done. I decided not to use xarray or pytables. Instead, I used H5Py.