Hi Juan,
How much RAM is currently installed on your machine? Also, prior to installing the Spatiotemporal Big Data Store, how much RAM was being consumed by other programs? There are many other variables that can have an effect on RAM consumption when using the ArcGIS Server, GeoEvent Extension or the ArcGIS Data Store products.
When all other variables are corrected for, a fresh installation of the ArcGIS Data Store product does not consume more than a few GB of RAM on the system. This value can increase depending on how much data is being written to database as well as other allocations of system resources.
Are you still experiencing this behavior?
-Chris