Google has announced that Fusion Tables will be shut down in 2019.
Fusion Tables were often used with data from the Google Public Data Explorer. There's no word on if that project will continue, but I would guess that it doesn't have long either. The Public Data Explorer site hasn't been updated since 2014.
One of the things that you could do with Fusion Tables was create maps that were representative of data sets. You can also do that by importing a Google Sheet into Google's My Maps tool. Watch this video to learn how to do that.