Creating an HR diagram from tabulated stellar data
With the Gaia Data Release 2, you can plot an HR diagram with a few million stars. From the Gaia website : 



The data can be accessed in the search tab, where you can specify the columns you want to display (phot_bp_mean_mag and phot_rp_mean_mag). There is a button at the bottom to export the results to a file on your computer. You can then plot one of the columns as a function of the difference between the other two.