A 'sparse' table containing device detail information for
installed and (possibly) active devices on this host system,
augmenting the basic entries in the 'hrDeviceTable' of the
IETF Host Resources MIB (RFC 2790).
Usage: UNLIKE the 'xcmGenOptionTable' in the XCMI General MIB
(which is a unique exception), this table of 'dictionary-based'
device details is used with DIRECT create/update operations.