As I was preparing/presenting pitch decks to the investors for our startup, there were only 3 terms about the market size:
1- TAM (Total Addressable Market): The maximum size for an opportunity
2- SAM (Serviceable Addressable Market): Segments of TAM, which you are capable of serving
3- SOM (Serviceable Obtainable Market): The portion that you can capture from SAM.
Therefore, I would say, Total Market is another way of saying TAM and there should be no difference between those 2 terms in terms of meaning.