I still do not understand your problem in detail.
The checkbox 'Generate' means that the next time you click the 'Generate' button we will regenerate those classes. This setting should be used if you do not want to overwrite your already generated code.
'Generate' has nothing to do with the 'Maps To' setting, which means in general that this table is mapped.
The settings 'Generate' is only available in the simple view, it is not available in the advanced view.
All the best,
the Telerik team
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