Potential risks of deleting G/L entry (Archive to new table)

Hi Experts,

Can somebody tell me the potential risks of deleting G/L Entry data (Archive to new table for later reference purpose) which are older than 7 years as customer don't want to keep old history coz of growing day to day data in this table. This table is already huge (over 100M records). For the deleted GL entries they will be posting a summary entries to reconcile the GL total overall.

Thanks in advance