sirajudeendk created a post for this back in 2011 (ORION NPM SNMP GET-TABLE FEATURE REQUEST) and I didn't see any response or place to vote for this and so I am posting it here again.
It would be really useful to be able to alerton the values found within a column of data from an OID table. In our current use case we are wanting to alerton the values found within the cbgpPeerAcceptedPrefixes (OID: 1.3.6.1.4.1.9.9.187.1.2.4.1.1) OID table. We can show the tables with NPM and see a nice line chart of the trends, but cannot alerton any of the values.
Within the SW MIB Browser we are presented with a message stating "Why are there multiple polled values? The OID you selected returns a column of data from a table. This poller requires a single value, so you may need to do a calculation on the next page."