SHALESHUDOT ON SHABBAT EREV YOMTOV

Question

WHAT DOES ONE DO ON SHABAT EREV SECOND DAY ROSH HASHANAH, SENOD DY SUKKOT, AND SHMINI ATZERET SMEONE TOLD ME TO EAT LUNCH BREAK IT UP AND BENTSH, WASH EAT AGAIN AND BENTSH. THIS SEEMS BIZARRE, WHY NOT EAT A LIGHT MEAL ABOUT FIVE PM? AND I HAD TO LAUGH ABOUT EATING SUPPER WITH TEIAVON, APETITIE, SINCE WE DIDNT GET OUT OF SHUL SIMCHAT TORAH EVENING UNTIL 10:30 PM ANYWAY WHAT IS A REASONABLE YET ACCEPTABLE WAY OF HANDLING THIS. THANK YOUYOU ALWAYS SEEM TO GIVE SNSIBLE ANSWERES