Dynamic Textures define how Unity materials are applied to the procedurally generated surfaces created by BuildR. You can read up more about them here.
The editor allows you to define the properties of this material so that you can control how it is applied to the geometry of BuildR.
The first field is Material and links to the Unity material that you want to use.
Texture is tiled relates to if this texture is to be repeated on surfaces. Things like doors and windows are not likely to be tiled. However, brickwork and wallpaper are more likely to be tiled. The repeat increments are controlled by the texture unit size. This value you can define how large the texture is physically in Unity units. Some brick textures may cover about many metres squared of wall, or some textures you want to use might be a single square meter.
If the texture is not tiled, you can modify the repeat values that will tile an untiled texture by an amount of times you wish. This might be great if you want to repeat a window multiple times along the x.