Many elementary and junior-high printouts are about lunch (給食, kyūshoku).
The Ministry of Education's guidebook for foreign children starting school
describes the usual pattern. Your school's paper is the one that counts.
What the guidebook says
Most elementary and junior high schools serve lunch as part of the school
day. Children usually set the food out and clear it away. The point the
guidebook states is a shared, balanced meal, not a restaurant menu.
Parents pay the lunch fee (給食費). A payment slip is the school's request
for that fee. Pay it the way the slip says, by the date on the slip.
If a child cannot eat something for a health or religious reason, the
guidebook says to talk to the class teacher (学級担任). It does not itself
describe a doctor's form. Schools now also follow the ministry's later
allergy guideline. Use that conversation, and the form the school sends.
A monthly menu (献立表) tells you the dishes and the days. If a day has
no lunch, the menu or a separate note says so, and you send a packed
lunch (弁当, bentō) only if the paper says to. Verify the month's paper
with the school.
Your child's dates, not the general ones
Add your child and ward. The timeline does the rest.