What's the usage/meaning of 就 in this case?
Given the context,

大的行李托運了，這個小的行李就隨身帶着。
The big baggage I checked, and this small one (I'm going to) carry with me.

you can rewrite I'm going to to will then be.

The big baggage I checked, and this small one will then be carried with me.

The translation of「就」to then should be clearer in this way of phrasing.