What is the difference between tenter and essayer

They are similar, but not quite the same. With tenter, there's an element of chance involved, more so than in essayer.

J'essaie les chaussures. -- I'm trying those shoes (on).
Je tente de traverser la rue. -- I'm attempting to cross the road.

Ethymologically, "tenter" is close to the English "tempt" and "attempt". A sign in the Parisian metro says: Ne pas tenter les voleurs -- Do not tempt the thieves.