The way the resume/cv functionality in JobRoller works by default is that the job seeker enters in their details via the resume form, rather than uploading one, so in that regard the only way you could potentially import the data in bulk would likely involve knowledge of mysql admin to do this from the database side. There is a plugin in the AppThemes marketplace called
FXtender pro which allows job seekers to upload their resume/cv, but again this isn't a bulk import feature. Ultimately there's not a straightforward way built into the theme to import the files. Thanks.