The hall as laid out in your sheet: four columns of round tables with the rectangular head table across the top middle. Left side is Tables 1–15, right side is Tables 16–30. Round-table seats run clockwise from the top; guests who shared a row in the sheet are kept side-by-side (on the head table, row-mates face each other). Dashed chairs are spare seats, and the Unassigned card holds guests who aren't in any table block in your sheet — click one, then click an empty chair to seat them. Every swap saves automatically and is restored when you come back; “Reset to original” wipes saved changes, and “Copy plan as text” gives you a paste-able backup.