(* I create a random pdf just as an example *)
pdf = Table[{x, RandomReal[]}, {x, 1, 10, 0.5}];
intpdf = Interpolation@pdf;
norm = Integrate[intpdf[x], {x, 1, 10}];
dist = ProbabilityDistribution[intpdf[x]/norm, {x, 1, 10}];

(* no parallelization *)
AbsoluteTiming[RandomVariate[dist, 1000000]][[1]]
(* Out = 7.28052 *)

(* parallelization on 8 subkernels *)
ParallelTable[
 AbsoluteTiming[RandomVariate[dist, 1000000]][[1]], {i, 1, 8}]
(* Out = {13.021, 12.7993, 13.8139, 13.417, 12.8863, 13.0874, 13.3788, 13.7836} *)