Tate spent most of his career (2010-13) with the Houston Texans and since then has spent time with the Cleveland Browns, Minnesota Vikings and Pittsburgh Steelers.
The workout is coming because Jamaal Charles is likely out for the year after initial tests determined he has torn his ACL. The Chiefs have Charcandrick West and Knile Davis on the roster now so they must be looking for some added help for those two. West is more of a passing down back while Davis is more of a north-south runner. They're not the same type of player. Tate had 34 receptions with the Texans in 2013 so he does have some experience catching the ball.
Tate, a 2010 second round pick, had his best season with the Texans in 2011 when he carried the ball 175 times for 942 yards (5.4 yards per carry). For his career, Tate has 540 carries for 2,363 yards (4.4 yards per carry) and 14 touchdowns. He also has 67 receptions for 347 yards in his career.