EmployeeContact is S$EMCTD.

This is based on the table prefix. You can either go to $LASRCDIR/{prodline}/modules/hr/bl/EmployeeContact.busclass and look at the line at the top that says "prefix is....",
or you can open a form or something on that BC in Config Console or Personalization and click the "view base LPL" link.

If you have SQL access, you can check the indexes for the EmployeeContact business class to find the prefix. For EmployeeContact the first index is EMCTDBYUNIQUEID.

I hope this helps.