It's quite possible that the log file can be greater than the database - it really depends on the number of transactions rather than the number of records. It's ok to change MAXSIZE but you need to be really sure that you want to (you can get all sorts of issues when the transaction log fills up) and you should consider actively managing the log.
Have a read through the documentation at
The Transaction Log (SQL Server)[
^] in particular the section on managing the size of the log.
I also find this website helpful
Managing Transaction Logs[
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