From what I understand here are what they are (but @Syed and @Abhishek can clarify/correct me):
Batch is the current scan count. When the decoder is looking to discover a signal, it will run batches of different settings to guess where the signal is. Little changes such as the Offsets, etc occur for each batch. Think of it like a cycle count.
Rs is the bandwidth size of the channel to listen for.
RSSI is received signal strength indicator. This tells you the strength of the signal coming in on the receiver. This is not necessarily useful on its own since it doesn’t have any information about interference or other problems in the wireless environment.
SNR is signal-to-noise-ratio. This is a very important measurement that indicates how much signal there is versus the noise (i.e. noise floor and various interferences). A negative number indicates there’s no chance of a useful signal, and for Outernet an SNR 2.0 or higher is necessary for getting a signal to lock and for the scanning to stop.
Pkt Sz is packet size. Pretty self-explanatory. This is how large a packet is.
SER is symbol error rate. In this case symbols are for BPSK.
CRC Ok is the number of packets that passed the CRC check, while CRC Errs are the number of failed CRC checks.
PER is packet error rate. A low number of packet errors with a high number of CRC Ok is what you want to see.
aFreq and aPkmn are related to BPSK signal detection.
SigDet is Signal Detected, 0 meaning NO, and 1 meaning YES.
State indicates the status of the demodulator, with this state flow: SEARCH, SIG DET, CODE LK, CONST LK, FRAME LK.