It is not possible to remove or manage the contents of 'Field History' values in Decipher. There are no functions to enable / disable / delete records.
Situations might occur when sensitive data is logged and needs to be remove due to compliance regulations, but there are no such convenient options to do it fast,
SQL query might be a workaround, but it is too bureaucratic to run it in proper and safe and approved way for big companies.
Link to current ticket:
How to turn off/manage Historical Reporting (Field History functionality) in Decipher v2.1 | Decipher (blueprism.com)