To tackle a challenge means taking it on, so if you set out to tackle the classics of English literature, you should be prepared spend a lot of time in the library.
The word tackle can be a verb or a noun, depending on its use. Today, the noun usually means fishing gear, but when it came into the English language it meant the ropes on a ship. If a ship was lurching about on the high seas, you dealt with that challenge by grabbing the tackle and wrestling it under control. Nowadays, people tend to think of tackling running backs and financial fraud, rather than ropes.