Looks like you’ve stored at least 4 Keys with Values. attrRet is a temporary workspace normally used to return the value from a Get request on a Key, but when you store a new key it returns a JSON string of all keys that have been stored.
Also from the great @thebearmay, is the Custom Note app that might be what you are looking for. I use it to set Battery type and another Battery Change Date on my devices to keep track and learn how long they typically last.