For storing dialogue, you could use something like
- scene name
- character name
- dialogue line number
e.g. for that example,
SceneTrainStation2_CharacterNPC1_Line1
I got this general idea from ThroughLine Games (who made Forgotton Anne) who have an automatic system in Unity where the dialog audio files are all imported automatically based on the file name. (I found this out from watching a behind-the-scenes meeting for their new upcoming game.)