rehearsal process on a realism based play

For a theater project how do you run a rehearsal? Do you have read-through process very often before you go on stage? like in some places or for some projects they often gather to have table read for some time for actors to discover the roles and structures of the play and get to know fellow actors role and how the play and emotion flows. Do you think this process is necessary or just after first time table read then go on exploring finding out the role and thins out on the stage with actors through give and take?