In any DIY store you can find wooden caps used to repair imperfections on your wooded forniture. You drimel out the gross part and glue a wood cap. These caps can be found in several sizes. You simply need to glue these caps together.
Here an example of the product.
And here some example.
The cilindrical piece is also found in the same bricolage stores.
As stated before, nothing spectacular, you can see the wood texture. But you can make a large amount of these colums in a very small amount of time and with even less money.