Is there something like tile pallet for Unity 3D ?

i have a lot of low poly modules for buildings (walls,doors and so on)and i want to make large level from it.Is there any way i can do it easier then manually designing every piece in scene ?

By tile pallet for 3D assume you mean like manually painting objects into a scene with your mouse? As far as I’m aware there isn’t a way to place objects into a scene like the way your describing, at least not like with the way the tile pallet works in 2D.

You could try using the snap to grid system if you want to place lots of objects without having worry about having to tweak their positions with the Move Tool manually. Of course that being said, adding any variation to your objects scale, rotation or height etc. will have to be done manually.

The snap settings are under Edit > Snap Settings…

Image from Gyazo

Hope this helps!