Google has added a new tab to the local panel for many restaurants. The new tab is for accessing the restaurant’s menu, and Google may show the tab if Google is able to pick out the menu items from the restaurant’s menu.
Sergey Alakov first noticed this, and I am able to replicate it for many local restaurants here. Below are some screen shots showing the menu tab next to the overview tab, and then when you click into the menu tab, a menu of a restaurant:
Google began showing tabs in the local panel about a month ago, after testing it for some time. The tabs shown are different based on the type of local venue it is. For example, restaurants might have a menu option, whereas hotels might show rates.