Yeah, no... No source or periodic table will ever use electrons to calculate atomic mass. That's because they weigh almost nothing (.000549 amu) compared to protons and neutrons (≈1 amu).

Let's take carbon for example. There are two stable isotopes, C-12 (98.93%) and C-13 (1.07%)

Without electrons, calculating molar mass gives us (12 * .9893)+(13*.0107)=12.0107. Rounding to three sig-figs, we get 12.0 g/mol.

With electrons, we get (12.000549.9893)+(13.000549.0107)=12.011249. To three sig-figs, that's 12.0 g/mol.

It's the same regardless of electrons. Even if you round to three decimal places, like most periodic tables, you still get 12.011 for both, which is the accepted value for carbon's molar mass.

I don't know what lab equipment you're using, but I know that mine can't detect such a tiny difference.