"To handle the workload" means to manage or deal with all the tasks and responsibilities that need to be completed within a certain amount of time. Full definition
With the prevalence of antibiotic use, pathogens are getting stronger and our immune systems less capable of handling the workload. (onnit.com)
If you're a film or photo student who needs a laptop for heavy video and image work, our main picks can't handle your workload. (thewirecutter.com)
He realized early that as development got more intricate and expensive, game developers wouldn't be able to handle the workload on their own. (theoutline.com)