The Deconstruction Table is a block added in Thaumcraft 4 that allows you to break down items into the primal aspects that they contain. It requires no fuel, but the chance of obtaining research points is minimal, increasing slightly based on the amount of each aspect the item contains.
"There comes a point in any thaumaturge's career where he is unable to progress with research due to his lack of knowledge.
One possible recourse is the Deconstruction Table. The table allows you to break down objects into their simplest parts which you can examine. There are limits however - the table breaks compound aspects into their component aspects until only primal aspects remain. During this process, much knowledge is lost and the best the thaumaturge can hope for is a single piece of primal knowledge.
For example, cobblestone (saxum and perditio) will be simplified into 2 terra and 1 perditio, only one of which will have a chance of being discovered.
It is also fairly slow and the fewer aspects the object has, the lower the chance to discover something."
Place items to be broken down into the top slot. Any aspects acquired from said items will be placed in the bottom slot. Simply click to remove these aspects and add them to your research points.