Are you trying to import a list of members into your database?
There is an abstract class designed for bulk updates of data - at the moment I think it is only subclassed by CsvBulkLoader. This is a good way to import a large amount of data.
However, it will still insert/update on a line by line basis. If the question is performance related, it sounds like you are looking for a way to queue up changes into a single transaction. That would be great, but AFAIK there is no functionality for this at present.