There are arrows to the left and right of it. A Red Dot is often located on a Dimension Tile. This dot indicates that there is additional information available about that particular dimension. City - search for Ottawa. Lets you put data in another order, eg.
Year can be in ascending or descending order.
Play with this feature and get comfortable with it. By simply clicking and dragging your dimension tiles around, this creates new displays of your data table. You are able to view more information from each dimension at once - potentially all information at the same time. This creates a large table with as much information as you wish to view. You can also do the reverse and 'show' items.