Let us look at the very first line. There is a
104 at the end of the line. Where does that
104 come from? It is the first number of the number(s) that are represented by
104 in the
next column. Since 104 is in the 0-255 range,
104 just represents itself.
The same procedure happens on the line at the end of which you see a
106. Where does that
106 come from? That
106 is the first number of the number(s) that are represented by
256 in the
next column. How? Since 256 is outside of 0-255 range, we have to consult the dictionary we have built. As given by the last column of the first line,
256 represents for two numbers,
116 104, of which
106 is the first one.
I will let you figure out why the above procedure is correct, where
101 on the last line come from and why the numbers in the
output column are correct.
By the way, it should be helpful if you can also take a look at the encoding procedure at the nearby lines when you try to understand the decoding procedure.