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.