RMS level graph as an export?

You can export the RMS values from the Acoustical Parameters module, pressing the button "Save Results to File". The default is to export just the table containing the computed acoustical parameters, in a TXT file. But if you select the alternate file format: Save As Type: Energetic IR (.CSV), you will get exactly what you need for all the octave bands plus A and LIN.
Then you open the CSV file in Excel, and format the chart as you like...

It is the third option, Ramsete Echogram (*.prn)...
I was referring to the Aurora for Audition version, of course. As always, the version for Audacity is slightly different (and less functional, in my opinion).
In the Audition version, also the Time History Analysis Aurora plugin features an "export to file" function, which can be used either for exporting the table of results, or the 1-ms time history of RMS values.
These features are not available (yet) in the Audacity version of the Time History Analysis module...

This is due to the fact that the file being created is ready for being copied and pasted inside a result file of the Ramsete program, which also computes the echogram in 10 octave bands.
Each value being exported is the "pseudo energy", and can be converted back in dB-SPL by the formula L=10*log10(value)
The A and Lin bands can be recreated easily in Excel, the LIN is just the sum of the 10 values, whilst for getting the A-weighted sum you must first multiply each "pseudo energy" value for the corresponding A-weighting factor, and then sum.
These are the 10 A-weighting factors, also expressed as "pseudo-energy"
0.000114815 0.002398833 0.024547089 0.138038426 0.478630092 1 1.318256739 1.258925412 0.776247117 0.218776162
Here you can find an example of an Excel file where these computations are done, and an SPL chart is created:
www.aurora-plugins.com/Public/Aurora-for-Audacity/Examples/