Goal:
Having SQL server 2012 with Tabular mode in my client computer.
Problem:
Is it possibly to install another sql server 2012 with tabular mode in my computer when I already have SQL server 2012 with Multidimensional and datamining mode in my client?

Yes, but you need to install another instance
If the underlying computer hardware can support it, you can install multiple instances of Analysis Services on the same computer and configure each instance to use a different deployment mode
http://msdn.microsoft.com/en-us/library/gg471594.aspx
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