Hi Wenyu,
The Mendix documentation suggests the following convention {PREFIX}_{Entity}_{Operation}
Assuming Table is your entity it will be something like ACT_Table_CheckAndBook
Where in this microflow you might have two sub-microflows SUB_Table_CheckAvailability and SUB_Table_Book, assuming you are checking availability in your application. This however is also for personal style and depending on how far you are in your journey, you might now already that you need the two sub-flows later on as well.
Hope this helps,
Jurre