Does Chargaff's rule hold true on these data?
From the table:
Ratios A/T and G/C are close to 1 with extreme at 0.77 and 1.05.
Ratios A/G and T/C are quite far away from 1, with several extremes around 2 or 0.5.
So, yes Chargaff's rule seem to apply quite nicely.
Why isn't the ratio A/T exactly 1?
The question of why the ratios A/T and G/C are not closer to 1 is interesting though. To fully answer this question I would need to go back into the primary literature who produced those numbers.
It appears that the three species of the list that have the smallest genome size ($\phi X174$, E. coli and yeast) are also the three species that show the greatest deviation from unity. The two species that have the largest genome size (maize and wheat) have the smallest deviation from unity. Overall, this suggests that this deviation is only a consequence of sampling error.
Did you say Sampling error?
This is just a small stat reminder
In statistics, sampling error is incurred when the statistical characteristics of a population are estimated from a subset, or sample, of that population. Since the sample does not include all members of the population, statistics on the sample, such as means and quantiles, generally differ from statistics on the entire population
Sampling error is not an error that a researcher does but an intrinsic property of the sampling process. Expected deviation from the true value is decreasing as the sample size increases, i.e. small sample size will show greater deviations (on average) from the true value than larger sample size.