Just in case someone else has this same problem - I tried all the things I could find in online help forums, and none of them worked. I finally did a Factory Restore from the Settings menu, and was eventually able to get the tablet back almost to its original state and re-download the few programs I had added to it, such as WiFi Transfer Pro and a weather app. Even after a lengthy delay (hours) in recognizing passwords to sign on to Google, the tablet took several hours to recover some functions, such as "Location". Obviously something more than just removing my Google contacts went wrong when I pressed what seemed to be a redundant, duplicated icon for Contacts. But the tablet is working normally again now.
Bill Hansen