I am using spacy package to package the NER model.
en_ner_model-1.0.0.tar.gz == 658794 KB
Does that size reasonable? or is there anything wrong in my package command?
It depends on what's in the model! If you've initialised your model with word vectors, that sounds like a reasonable size, because the vectors will of course be packaged with the model. The package size can be anywhere between ~20mb and 1gb.