When the selected audit capture file contains syslog information then the output will be displayed in a separate tab.
Example of a Wireshark trace containing syslog information :
Selecting one of the links in the FileName column opens the syslog text file.
In the example this is VoIPAnalyzer_syslog__SRC_10_0_0_1__DST_10_0_0_2.txt and selecting the link displays the contents :
More information on syslog can be found under https://en.wikipedia.org/wiki/Syslog.