The plastic bags that deli luncheon meats and cheeses come in and the hard plastic containers that other deli items come in can be re-used to pack your lunch the next day.
Note: since the plastic baggies contained perishable products take care to re-use them immediately (don’t store them outside of the fridge) and toss them after re-using one time. You can however wash the hard plastic containers to re-use them more than once.