To use the ClientDataSet component on Linux Delphi applications you need to distribute the libmidas.so library, the Linux equivalent of midas.dll. We failed to deliver it as part of the 10.2 Tokyo release, and it has been made separately available at:
http://cc.embarcadero.com/item/30765
The additional file belongs to the redistributable list and you should also copy it to C:\Program Files (x86)\Embarcadero\Studio\19.0\binlinux64 -- ultimately it doesn't matter much.
You can add that file to the application deployment, so that it will be copy to the Linux box via PAServer, or just copy it manually to the Linux box. Of course, you need to do so only if you want to use the ClientDataSet component in a Linux application. While we recommend the FDMemTable component as a replacement, if you have existing code based on ClientDataSet you might want to use that older solution.