Your dream seems to weave together themes of family connections, transitions, and perhaps feelings of visibility or recognition within your relationships. Let's break it down scene by scene.

1. Family Gathering in the Restaurant: The setting of a family meetup suggests a desire for connection, unity, or perhaps a need to address familial dynamics. The fact that it was light outside and the restaurant was quieter could symbolize a peaceful environment or a longing for harmony within the family. Sitting with your back to the door might indicate a feeling of vulnerability or a lack of control over the situation, as you are not facing incoming energies or changes.
2. The Black Dog: Dogs often represent loyalty, protection, and companionship. The act of the dog escaping might symbolize feelings of anxiety or concern about something or someone in your life. Your attempts to bring the dog back inside could reflect your desire to maintain control over situations or emotions that feel chaotic or fleeting. The presence of your husband's friend might suggest you are seeking support or assistance in navigating these feelings.
3. The Walk to the Restaurant: The contrasting scenery—a canyon on one side and shops and restaurants on the other—could represent the balance between risk and security in your life. The canyon may symbolize deep emotions or challenges, while the shops and restaurants signify comfort and community. This pathway could reflect your journey through life, navigating between vulnerability and safety.
4. The Encounter with Your Brother and Mother: The interaction with your brother and the object he received may symbolize feelings of comparison or competition within your family. The fact that your mother could not see the object, while your father could, may reflect feelings of misunderstanding or being overlooked in your familial relationships. This could indicate a desire for validation or acknowledgment of your own experiences or achievements.
5. Seating Arrangement at the Long Table: Your seating position at the long table, where you are facing the entrance, suggests a role of observation or a desire to be aware of what is happening around you. This could symbolize a need to assert yourself within the family dynamic or a desire for clarity in your relationships.

Overall, this dream could be highlighting your feelings about family connections, the complexities of relationships, and your desire for recognition and understanding. It may be beneficial to reflect on your current family dynamics and consider ways to foster communication and acknowledgment among family members.