Similar problem with table, when my wife started putting 25 pound dog food bag on the table I knew it was time to fix it. Wall bracket was secure to the wall, bracket that held the table was loose (cause of squeak), replaced all screws slightly larger than the originals, self-tapping, fixed! Pull the table all the way out and flex it up and down and you will find the squeak. Good luck.
2018 Allegro Red 37PA