She is probably known for many roles, including being the voice of Perfect Peter in Horrid Henry, Harry in Harry and His Bucket Full of Dinosaurs, Raggles and Bluebird in Everything's Rosie, and Mowgli in The Jungle Book.
Tate's acting debut came in a 1991 episode of The Bill and since 1999, she commenced work in voice acting, mainly in children's programmes, starting with the U.S. version of Bob the Builder and also on Dream Street, voicing Half-Pint the milk float.
In late 2000, she began to do the UK dubbed voices of Lily, Mrs. Frog and Tad (2000-2002), alongside the late Susan Sheridan, for LeapFrog toys. After 2002, she dubbed only Lily's voice and Mrs. Frog's voice for these toys.
In 2006, Emma began to voice Perfect Peter in the TV adaptation of Francesca Simon's book Horrid Henry.
In 2010, she began to appear with Horrid Henry co-star Joanna Ruiz in Everything's Rosie, voicing the main characters. Ruiz voices the title character while Tate voices Raggles the rabbit. In the 2013 video game Broken Sword 5: The Serpent's Curse, she voices the female lead Nicole Collard and other minor roles.