After your panel interview, about 6 to 1, you will gather in a meeting room whereby some food and beer will be served. Once all 10 of you guys have completed the interview, you all will gather there. All the panel interviewers will be there and you got to mingle with them, talk about anything, but usually related to flying, the company, etc. Be at your best and don't ask stupid questions (eg, Do I get Business class to rest? or Do I get to transfer to SIA from SIA Cargo? Or Can I fly the A340-300). You can ask how's your chance for A380? How's the life like? How many long haul per month, etc. The interview may be over, but the interviewers will still be observing you. Feel free to eat something, cos many will just listen while the interviewers drink beer and eat and talk to you guys.
No hard and fast rule, but if you show interest in aviation, not that difficult. But remember to address all interviewers SIR!