if you have the Table module but you forget to put the SideviewUtils module into the page, then you don't get an 'unknown module' error, because the module is technically there. what you get is actually a JS error when the module is initialized because it tries to call out to the shared code in the SideviewUtils module and it isn't there.
If Splunk says that you don't have the Table module, then either
1) You don't have the Sideview Utils app installed
2) You have Sideview Utils installed, but it's the old version from Splunkbase (1.3.5), which won't have a ton of stuff that was introduced in the 2.X versions. Notably the Table module wont be there. Note that if you go to the Manager section and it tells you that you have the latest version already, it only knows about the version on Splunkbase. Get Sideview Utils from the Sideview site http://sideviewapps.com/apps/sideview-utils The latest version is 2.4.7 and soon to be 2.4.8. The 2.X versions are fully backwards compatible with old usage from 1.3.X, so go ahead and upgrade, and you can check out the release notes to see just how much you're missing out on.
3) You have installed Sideview Utils manually by moving the directory into $SPLUNK_HOME/etc/apps/ but you haven't restarted SplunkWeb. (not very likely)