Przytula,

The toys in the bookcases take up a HUGE amount of space. You have chosen the biggest of the biggest models, which you then show so small that none of the details are visible. I suggest you choose simpler, smaller models. You will hardly notice the difference, but rendering may become possible.

Here are a few suggestions for your largest files:
Chopper - 39 Mb - alternative 400 Kb
Dart board - 12 Mb --> alternative 114 Kb
Plane - 12 Mb - alternative 323 Kb
PC tower - 9 Mb - alternative 43 Kb
Starwars - 7.7 Mb
Fan - 6.8 Mb - alternative 70 Kb
Mountain bike - 6.1 Mb - alternative 1 Mb
Xbox - 5.4 Mb - alternative 1 Mb

Good luck,

Hans