This is possible, I need this very often.
what you would need is a relation between this two tables.
for example in your schema for media you would need this:
<field key="medialist_id" dbtype="int" precision="11" phptype="integer" null="false" default="0" />
<aggregate alias="MedialistItem" class="yourMedialistClassname" local="medialist_id" foreign="id" cardinality="one" owner="foreign" />
then you can have in your media-configuration on the tab MIGXdb Settings:
Check Resouce: Yes (in this case its not a resource but a record of your connected table to check for connection)
Join Alias: MedialistItem
this should be it.
the default-update-processor should automatically fill the medialist_id - value when you save a new record and the default-getlist-processor should filter them in the grid, which are connected to the medialist-record.