Hello,
To determine growth rate of a single table, you'd have to setup a process to collect some history about the space used by the table. The rate would depend on the frequency at which you collect the space data.
To determine the size of a table run the sp_spaceused stored procedure:
Syntax:
sp_spaceused [[ @objname = ] 'objname' ]
[,[ @updateusage = ] 'updateusage' ]
Reference: http://msdn.microsoft.com/en-us/library/ms188776(SQL.90).aspx
Hope this helps.
Best Regards,
~Rusty