what they are for:
aliases: fs_cli command aliases
calls: list of currently active calls for show calls
channels: list of currently active channels for show channels
complete: tab complete data for fs_cli
db_data: for the db application data storage
group_data: for the group command data storages
interfaces: for the show interfaces command
nat: active nat mappings
recovery: state data for call recovery
registrations: central data repo for storing registration data
sip_authentication: storage of sip nonce info
sip_dialogs: sip current dialog info, used for presence
sip_presence: used for presence state
sip_registrations: used for data for active sip reg
sip_shared_appearance_*: used for another kind of sip presence
sip_subscriptions: to store active subscriptions
tasks: for the task scheduler