Tablature vs. musical notation
Most guitarists don’t try to know the standard musical notation. The good news is with tab, there is no need to learn it either. Just like notation, you can read tablature from left to right. Actually, the vertical lines refer to the end of each bar so you can keep time. But the horizontal ones don’t refer to the strings of the guitar. Moreover, in standard tuning, you will see that the 6 lines are called E, A, D, G, B and E. They are read from the bottom to top.
Actually, each position of the finger is shown by a number on the horizontal lines. These numbers give a certain fret position. Let’s take an example. On the second line, a number 3 is an indicator of the note of D, and it has to be sounded at the fret on the B string. You won’t find an indicator for the notes length with tab. Therefore, there is no equivalent of a crotchet or quaver symbol. This problem can be addressed by ear. Another way is to listen to the recordings of the thing that you are trying to learn.
The numbers that start from the left and go all the way to the right on the tab are an indicator of a melody. If you see two or more numbers on top of each other, know that they refer to multiple strings or all of them. So, they should be played just like a chord. It is very easy. You just need to practice for a few minutes daily.
The down facing arrows over the tab mean that you should play a downward strum. On the other hand, the reverse means you should do upstrokes. This give you a pretty good idea of the rhythm.
Melody and other advanced techniques
Unlike chord patterns, you will take a bit more time to learn a melody. As a matter of fact, if you practice scales, you can easily determine which finger you should use when the tablature requires a fret position, especially if there you have to make a long reach.