I live in London TMA and also take my box on three overseas holidays per year. I am not interested in keeping routes/callsigns. I am not a 24/7 man and prob only operate the radarbox for circa 15 hours per week (with more when I am on holiday). In a standard year I get over 16,000 individual aircraft on my MyLog. Every few months I clear the callsign & associated routes info using the dropdown menu.
Then every year on 31 December, I save/download the MyLog contents to CSV and then convert the CSV to XLS. Consequently, I permanently store one years worth of records in XLS format. After the CSV download, I delete all aircraft data from MyLog, such that the MyLog staarts again from zero aircraft as I switch on for the first time after 1 January.