Determining noise spectral density
No, you have completely misinterpreted the data provided.

First of all, sample rate does not correlate to operating mode as you tried to show with your notation &mdash; they're actually completely independent parameters. Besides which, as shown in Table 10, power consumption increases with sample rate, not decreases.

Unless otherwise specified, you pretty much have to assume that noise is white &mdash; equal power at all frequencies, which implies that the RMS value is proportional to the square root of the total bandwidth.

Unfortunately, they do not specify the bandwidth associated with the data in Table 5, so the only thing you can use it for is to get an idea of the relative noise levels of the different operating modes. You can't infer anything at all about the PSD from it.