What is the meaning of the astral world?

The Astral is a world of thought. Spirits construct what they have and realise what they possess by their thoughts. 

Their thoughts produce things. Everything they see is a reflection of their thoughts. Every object is a consequence of their thoughts, made manifest in form, and each means something.

In the Astral, spirits learn to distinguish what is best to bring out in the objective, for thoughts are things real, good or bad, according to the power they give them. They manifest themselves in many forms—they are their thoughts merely expressed in forms. 

They expect to see a room and we do. 

When spirits think of the room's furnishings, their thoughts form the kind of setting they like—furnishings to which they were accustomed in their physical life. 

Suppose you had been thrust from the physical body of the material into the astral, and at that time had been living in cramped circumstances. When you came to the Astral, your thought would not have changed, and immediately when you had overcome darkness and weakness, your mind would reach out and bring forth forms of your earthly existence. 

You would see again around you the furnishings and thought pictures of your earthly life. Spirits bring from the earth plane, when they come here, their every thought of the material. Some are so filled with these thoughts that they believe for a long time that they are existing, as they did upon the earth plane.