This is actually really good functionality that has been bolted onto something that has been around in OneWorld forever. The F98613 table has been around since time immemorial - and by caching certain static tables into this list, you'll likely see some performance improvements in E1.
To answer Toms' question - the F98613 is a system table and is therefore across the entire system. So if you make a change, it'll affect ALL servers. Its not recommended to create multiple versions of this table by environment - it'll take more management, and could come up with strange issues...!
Now, since each of the Enterprise Server Kernels is running by environment (as is, we hope, your Web Instances) - then each will have its own "cache" version.
Cache should time-out eventually - which is now updated by the P99410 - so if an instance isn't being used, then the cache (and therefore, the utilized memory) will eventually clear up.
However, you definitely need to be careful WHAT you cache. If you cache tables that are actually frequently updated, you'll put extra load onto your system - and that extra load could be significantly more than the benefit of the caching provides. However, you should be able to judicially be able to identify what tables are updated frequently or not.
