Decision Table making:
| First Name | Last Name | Email Format | Phone Number Format | Appointment Availability | Expected Message |
| Valid | Valid | Valid | Valid | Available | Schedule appointment successfully |
| Blank | Valid | Valid | Valid | Available | All fields are required |
| Valid | Blank | Valid | Valid | Available | All fields are required |
| Valid | Valid | Invalid | Valid | Available | Please enter a valid email ID |
| Valid | Valid | Valid | Invalid | Available | Please enter a valid mobile number |
| Valid | Valid | Valid | Valid | Not Available | Please choose another date/time |
| Blank | Valid | Valid | Valid | Not Applicable | All fields are required |
This decision table covers all the possible combinations of inputs and their expected outcomes based on the conditions you provided.