Call is fine. This is such a non-standard play you can't be terribly confident of a range - I'd assume medium strength hands that don't want to play flops but are confident they're ahead now. But I don't think you can limit the range to solely pairs; if 88 is in there, AQ probably is as well at some frequency (and maybe some aces below that).
Stats can be misleading with small sample, but vs that player type I think jam is pretty pair heavy & might even be some stupid strong range of AKo+ , JJ+ . But again small sample and strange move means you are basically just guessing and praying.