Choose the number of kernels used by ParallelTable

Another way from the menu (if accessible): Edit $ \rightarrow $ Preferences $ \rightarrow $ Parallel $ \rightarrow $ Local Kernels $ \rightarrow $ (Number of local kernels to use) Manual setting

You can launch as many or as few kernels as you like, see LaunchKernels and CloseKernels. Parallel functions will use as many as are currently running.

E.g., LaunchKernels[3] would launch 3 additional kernels. Before you run any parallel commands, simply launch precisely as many as you need. Then automatic launching won't be triggered anymore.

If you already launched too many, use CloseKernels to close as many as you don't need.