Divorce Case Is Entered in T. F.Mrs. Gwen Slack filed suit for divorce from Kenneth M. Slack Tuesday in district court charging mental cruelty.She asks title to all community property, including a 1959 Chevrolet, a 1950 Plymouth and household furniture and .appliances, attorney fees, and requests that the court restore her former name of Gwen Phillips. In addition, she asks that Slack be required to pay all communitydebts.They were married Nov. 5,1950, at Elko, Nev., and have no children. Edward Benoit, Twin Falls attorney, is representing Mrs. Slack.