List creation - the filters at the top of the page allow you to create a preview of your filtered contact list. This list will become usable for for export and email blast purposes once you name and save it.
View list - to view a list, you would select it from the Saved Lists dropdown. The filters that were chosen originally will be applied and a preview of the current version of the list will be displayed.
Please keep in mind - when you save a list, you are really saving the search criteria for that list - so when you access it later, you will be getting the most up to date version of the filter results.
The email blast is intended to send a quick email note out to a saved list. If you need to send an HTML email or manually edit the list (i.e. manually add/delete recipients) prior to sending, you should export your list and use it with an email client (Thunderbird, Outlook, for example) or an email list service (Constant Contact, for instance).