I don't know a lot about databases and I do know that there has been a huge amount of work that has been put into nopcommerce to give it the functionality that it has but 523Mb seems very large for a near empty database and I am thinking that I may have a problem with old databases on my host not being deleted properly.
If anyone can give me rough figure of what a fresh install, with sample data, should be that would be great.
This is a blank install. Though I have uninstalled a previous nopcommerce instance. I think this is just an error with my host. everything works fine but I have installed/uninstalled a number of databases in the past and I don't think they have been properly deleted from my account even though my control panel tells me I only have one database installed.
I have put in a ticket to my host to hear what they think the problem is. I will post the answer in case anyone is interested or maybe had the same problem.