Possibly blocking may be the primary issue that makes you feel huge traffic in-spite of NOT HUGE data in the database.

Do you use CAML query designer for sharepoint to read data from database?

CAML designer by default copies all the columns even though most of them are not required for the application. Try to chose only required column from the table to populate data in sharepoint dashboard/web.

And sharepoint, by architecture, uses MAXDOP = 1 query hint , as per my knowledge untill version sql 2008 R2.

Hope this helps to troubleshoot.