AES MixColumns using L and E lookup tables
The values in the tables are listed in hexadecimal; hence the Log table maps $\mathtt{87}$ to $\mathtt{0x74} = 116$.  Similarly, it maps $\mathtt{02}$ to $\mathtt{0x19} = 25$, and $(116 + 25) \bmod 255 = 141 = \mathtt{0x8D}$; looking up $\mathtt{8D}$ in the Exp table gives us... $\mathtt{15}$ (actually, $\mathtt{0x15}$).