Its not quite clear for me what you are looking for. if you talking about a Talend schema: The answer is clear, there is not way to define a schema at run time of a job.
If you talk about a database schema and you have a create script you want to run automatically, this is quite easy to do.
You cannot automatically define a job which creates a database schema and reads the csv files according to this schema at the moment. For sure it would be possible to write a component which maps a table schema to a head line of a csv file without need manual interaction but we do not have such component yet in the Open Source release.
In the enterprise release you could use the Dynamic schema feature. This allows you to read an csv file and forward the flow to a database component without you have to know anything about the number or types of the fields.