What you'll probably need to do is put a place holder in the fluent nhibernate mapping for the table name and then replace it after you build the mappings.
Take a look at the following article and I think the first code sample will give you an idea of what you need to do.
http://ayende.com/blog/3294/dynamic-mapping-with-nhibernate
I was able to do this. Here is a rough example:
var fluentConfiguration = Fluently.Configure(NHibernate.Cfg.Configuration().Configure())
.Mappings(m =>
m.FluentMappings
.AddFromAssemblyOf<OrderMap>()
.Conventions.AddFromAssemblyOf<PascalCaseColumnNameConvention>())
.ProxyFactoryFactory("NHibernate.Bytecode.DefaultProxyFactoryFactory, NHibernate");
var config = fluentConfiguration.BuildConfiguration();
foreach(PersistentClass persistentClass in config.ClassMappings)
{
if(persistentClass.MappedClass == typeof(Order))
{
persistentClass.Table.Name = "Dynamic Table";
}
}
//You could substitute above for each loop with linq unless you have a bunch to replace then use foreach
//config.ClassMappings.First(x => x.MappedClass == typeof(Order)).Table.Name = "Dynamic Table";
var sessionFactory = config.BuildSessionFactory();
using(ISession session = sessionFactory.OpenSession())
{
Order order = session.Query<Order>().FirstOrDefault();
}