The Starlight Crafting Altar is a block added by Astral Sorcery. It is the second tier of crafting altar and is used throughout the Attunement chapter of the Astral Tome.
The Altar works similarly to its predecessor the Luminous Crafting Table, and can make all recipes that the latter can. However, it has 4 extra input slots that can be used for more crafting recipes, and gather Starlight much more efficiently, but requires a complete structure to be built around it in order to do so.
The complete structure is 9x4x9 and requires (in addition to the Altar):
This will directly change the Luminous Crafting Table instead of dropping the output in the world.
Astral Tome entry
The Starlight focusing abilities of the Luminous Crafting Table and addition of a Starlight reservoir make it a significant upgrade to a normal crafting table. However, even that can be improved upon. The table can be engineered into a larger altar with reinforced extensions designed to capture and support increased Starlight flow.
In order to focus enough Starlight to actually make use of the extensions however, a large Starlight collection structure made of various types of marble is required.
The Starlight reservoir in the crafting altar is not only greater in size compared to the Luminous Crafting Table, it has special properties that cause it to turn red if the collection structure around the table is incorrect, or incomplete.
In order to upgrade a Luminous Crafting Table into an altar, it will need to be placed in the center of the marble collection structure with a night view of the sky, with the items arranged in the table. Then the ritual can be started with the Resonating Wand.