How to assign different textures to one mesh?

I am generating a mesh at runtime(background made out of quad tiles) and i would want to assign different tile textures to the background. Creating separate game objects for each mesh is not an option as having ~5000 tiles as game objects would not work well. How would i do it?

 

Different Textures go on Materials.

If you need different Textures on a Mesh, you need to use different Materials.

In order to use different Materials your Mesh must have submeshes.

Each submesh corresponds to a material.

I have a cool procedural geometry pack I fiddle with from time to time called MakeGeo.

EDIT: I just threw a multi-material example in there. Look in folder :

makegeo/Assets/makemultisubmeshquad

MakeGeo is presently hosted at these locations:

https://bitbucket.org/kurtdekker/makegeo

https://github.com/kurtdekker/makegeo

https://gitlab.com/kurtdekker/makegeo

https://sourceforge.net/p/makegeo

 

You only need one material here, but you have to set UVs fitting to the generated mesh. Each quad would have its own UV segment on this UV. The texture of the material then is a texture atlas for these quads and would look similar like this: