、・・・、。
The servants who've gathered are, all together… o-over a hundred!
Literal
Gathered servants-[polite-さん]-tachi [topic-は], total-count... o-one-hundred people near is.
The stuttered ひゃ is the first syllable of 百 (hyaku, 'hundred'), stretched out with hesitation as the speaker is about to deliver the shocking figure. 総勢 is the compact formal noun for 'total force / total number (of a gathered group).' ひゃ、百人近い → 'near a hundred people.' 使用人さんたち uses さん as polite address to the servants (despite their lower social role), and たち as the pluralizer for people — together 'the (esteemed) servants.' The whole sentence captures the wonder of seeing a huge number for the first time.