How to Identify a System Query

In sys.dm_exec_sessions there is a column named is_user_process. 0 means system process, 1 is user process. MSDN link here.

To show connection to your tables I post query that I am using for monitoring activity:

SELECT distinct 
        s.session_id,
        s.login_name,
        c.client_net_address,
        w.wait_duration_ms,
        w.wait_duration_ms/1000/60 as [min],
        w.wait_type,
        w.resource_address,
        w.blocking_session_id,
        w.resource_description,
        CAST (st.text as nvarchar(max)) AS [SQL Text],
        s.is_user_process
FROM sys.dm_exec_sessions S
LEFT JOIN sys.dm_exec_connections AS c ON S.session_id = c.session_id
LEFT JOIN sys.dm_exec_query_stats qs on c.most_recent_sql_handle = qs.sql_handle
INNER JOIN sys.dm_os_waiting_tasks AS w ON w.session_id = s.session_id
OUTER APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st
ORDER BY s.is_user_process DESC, w.wait_duration_ms DESC