SQL 2008 RTM Temp Tables
Temp table usage is going to be totally up to your applications which have their databases on the SQL Server, or that are using the SQL Server.  For example the monitoring application itself could be using dozens of temp tables while it gathers up data.

As for the memory usage, SQL Server will by default use up as much memory as it needs to.  Every time is needs to modify data it loads that data into memory and then leaves that data in memory until the SQL Server needs the memory for something else.  In other words high memory usage isn't something that needs to be worried about as it is totally normal.  That said you'll want to cap the amount of memory that the SQL Server has access to so that it doesn't use all the memory on the server.