There are food surpluses.
You have to consider that most of the European countries are small and can generate very small surpluses. Time when countries had significant reserves of grain, beef, and other food product is gone. It is not economical to store so much food. It is much cheaper to bring needed food from across the globe, but someone has to pay for it. The other issue will be housing. Europeans are renters (like in Germany where 2/3 people rent) unlike USA where majority people pay mortgage or own homes. This housing model will require significant public resources that I do not see it happening without widespread wealth transfers, deficits, and taxation.
Once refugees will leave migrant centers, they will end up in ghettos without any job prospect as is the case across most of Europe. Unemployment rate for young Europeans is already between 25%-40%, and Europe is losing entire generation to people who will never have stable job developing working ethics due persistent unemployment. While current welfare model eliminates extremism, it will not last forever. 83 millions of Europeans are poor. Another 48 millions are socially deprived (EU poverty). This is a huge number of 120-135 million people.
The fate for majority of the refugees will be no good job prospect, poor quality of housing, and social exclusion. Europeans will instead multicultural society promised by their ultra-liberal media and politicians are finding themselves in economic conditions known by 3rd world. Sweden, Belgium will most likely turn into 3rd world country by 2030 (Sweden will be 3rd world country in 2030.). I would say it is too optimistic. Europe is already 3rd world by visiting every capital from Paris to Helsinki or between Dublin and Athens.