You can see these snippets in action by Googling ‘Nikon D7100’. The middle result here contains data about resolution, weight and display size. 

You can also see these snippets in action on a search for ‘Superman’, just in case anyone doesn’t know he’s from Krypton. 

According to Google: 

We use machine learning techniques to distinguish data tables on the Web from uninteresting tables, e.g., tables used for formatting web pages. We also have additional algorithms to determine quality and relevance that we use to display up to four highly ranked facts from those data tables.

Here’s the table on the dpreview page which Google has extracted the data from: 

The listings with structured snippets do stand out a little bit more in the SERPs, but whether this be enough to increase CTR remains to be seen.