As best I can tell, the Census Bureau has no more formal metadata documentation for the ACS. For our CensusReporter.org project, we process that file and use the indents to quantify the "indents."
You can query our API to get our understanding of tables: for the one in your screen shot, you'd use this URL:
api.censusreporter.org/.../B05009the response is JSON formatted. Some more documentation about our API in general is at
github.com/.../API.mdI would like to organize some more formal input to the Census Bureau about how we—the data user community, not just Census Reporter—would benefit from formal structured metadata, but I'll admit that I have not found the time to actually take steps towards it.
Maybe with the upcoming 2014 release, we'll be able to document some things more specifically.