Getting a DB Error: unknown error when entering and saving phone number
There is a mysql function that is called to save a normalized phone number (stripping spaces and so on). You seem to have a problem as mysql can't load this function

Cannot load from mysql.proc. The table is probably corrupted

This might be several issues and potentially indicating bigger issues, database corruption should be handled seriously.

The indicated fix might work:

mysql_upgrade 


Backup the database first. if it doesn't solve the problem, restore it on a different server (or on your laptop) and check if you can get a working civicrm there.