Avoir du pain sur la planche is a French expression that translates literally to “to have bread on the board” and means “to have a lot on your plate” and “to have a lot to do”.
avoir du pain sur la planche
to have a lot on your plate

Example sentences
Désolé, je ne peux pas te rejoindre ce soir. J’ai du pain sur la planche.
Sorry, I’d can’t join you this evening. I have a lot to do.
J’aimerais bien passer le weekend chez vous, mais j’ai du pain sur la planche, il va falloir que je reste à la maison.
I’d love to spend the weekend at your place but I have a lot to do. I’m going to have to stay home.