Usually we alternate between a medium sized tray with transferring activities (rice/ lentils) and small community playthings sand/ water tray. Recently we have had rice on the "cooking" table for children to use when pretending to cook (will try to find some pics), however they seem to have become very complacent and spilling it all over the floor (they do sweep up but it really is a job for the vacuum). So we have gone back to basics, with a tiny tray. One of the children has been having a bit of a problem getting the tray out without the bowls slipping so transferred to wider rimmed tray, still no success but today I had a brainwave add some non slip fabric and hey presto problem solved. Maybe we can get down to learning how to transfer carefully now.
"Reflection Montessori pedagogy is based on allowing children to move toward self-mastery." Tim Seldin and Jonathan Wolff