Over what period of time? If that's in a day then it seems unusual (unless you have very busy sites). If it's in a month then it's not unusual.

Do you have logrotate rotating the log files? You can also set logrotate to compress them, which will reduce them in size significantly.

You can then experiment with how frequently you rotate the logs (i.e. daily or weekly) and how many rotated logs you keep to refer back to.

How to use log rotate for virtual​ hosts.

Can replace this CustomLog /var/log/apache2/access-example.com.log combined

With CustomLog "|bin/rotatelogs /var/log/logfile 5M" common