Archived Feature Class Updated?

[BoGuo]

We were baffled that some of the recent edits (via ArcMap 5.1 eith Roads and Highways extension) to an archive-enabled LRS feature class had not shown up in the FME-based ETL processes.  It turned out that the edits went into the the archive H table instead.  Could anyone tell us if this was a bug or user-error?  

[BoGuo]

OK, we dug further and realized the H table represents the entirety of the event table.  It was how archiving was supposed to work.