Simon Vaughan points out that the formula for the error on the excess variance (equation 5.6) assumes Gaussian white noise, which is rarely the case. This is discussed further in Vaughan et al, 2003, MNRAS, 345, 1271. In addition, he notes that excess variance is not really a test for variability but an estimator for the variability amplitude.
In table A1.5 the Ne V ionization energy should be 126.2 eV, not 12.62 eV.
In table A2.4 the mass of the proton should be 1.672622e-24 g, not 1.672622e-28 g.
Table A4.2 has no entry for the Objective Grating Spectrometer (OGS) on the Einstein Observatory.