What you can do is explicitly import all additional decoding tables that come with the package like so
# This fixes an issue with PyInstaller... is there a more elegant solution perhaps?
from unidecode import x000, x001, x002, x003, x004, x005, x006, x007, x009, x00a,\
x00b, x00c, x00d, x00e, x00f, x010, x011, x012, x013, x014, x015, x016, x017,\
x018, x01d, x01e, x01f, x020, x021, x022, x023, x024, x025, x026, x027, x028,\
x029, x02a, x02c, x02e, x02f, x030, x031, x032, x033, x04d, x04e, x04f, x050,\
x051, x052, x053, x054, x055, x056, x057, x058, x059, x05a, x05b, x05c, x05d,\
x05e, x05f, x060, x061, x062, x063, x064, x065, x066, x067, x068, x069, x06a,\
x06b, x06c, x06d, x06e, x06f, x070, x071, x072, x073, x074, x075, x076, x077,\
x078, x079, x07a, x07b, x07c, x07d, x07e, x07f, x080, x081, x082, x083, x084,\
x085, x086, x087, x088, x089, x08a, x08b, x08c, x08d, x08e, x08f, x090, x091,\
x092, x093, x094, x095, x096, x097, x098, x099, x09a, x09b, x09c, x09d, x09e,\
x09f, x0a0, x0a1, x0a2, x0a3, x0a4, x0ac, x0ad, x0ae, x0af, x0b0, x0b1, x0b2,\
x0b3, x0b4, x0b5, x0b6, x0b7, x0b8, x0b9, x0ba, x0bb, x0bc, x0bd, x0be, x0bf,\
x0c0, x0c1, x0c2, x0c3, x0c4, x0c5, x0c6, x0c7, x0c8, x0c9, x0ca, x0cb, x0cc,\
x0cd, x0ce, x0cf, x0d0, x0d1, x0d2, x0d3, x0d4, x0d5, x0d6, x0d7, x0f9, x0fa,\
x0fb, x0fc, x0fd, x0fe, x0ff, x1d4, x1d5, x1d6, x1d7
The PyInstaller parser will then include them in the distribution. Note, however, in this case the data variable gets imported into your script.