More than a hidden feature, let's say it's a different way of thinking
I'll explain what i thought
Being a web developer for remote times (i started working in the sector in 2003) i saw the evolution of HTML about it
first the templates were made using the tables
So it was natural for me to use tables as a templating system for the columns
Maybe no one had ever thought about it before, but i had used it in the past I came naturally to me..
Old days, when the layout of a website was all organized through tables.
At first, it might seem difficult, but once you understand the logic, it becomes quite easy.
Exact dear, i was used to doing quite complex layouts, those who passed the graphs in PSD
I was also used to cutting myself the various pieces that i needed to compose the final layout
In those days, objectively horrible layouts were made, i made an ecommerce for a business of all rounded rabbits .. a hell!
anyway, for start you can do normal table with border, this help much for understand