How to create a Complex Table (Doesn't have a complex header)

Hi, I am trying to create a table similar to the below figure in Vaadin 7.

I am working on these 3 solutions. Still I don’t have a clarity on what I should go ahead with implementation.

  1. Using Column Generator. I referred

  2. Having a table inside a table item. But I am finding difficulty in creating that also. I am unhappy about the look and feel.

  3. Searching for if there is anyway we can merge the cells to form a block.

Any help in this regard, is appreciated.

What about using
, instead of Table?