"To digest the material" means to understand and process information or knowledge in a way that makes it easier to comprehend and remember. Full definition
Your pet can not digest this material, so it will get stuck in and damage her intestines. (pawmettolifeline.org)
We offer students online access to the curriculum, affording them the opportunity to digest the materials at their own pace. (csscs.org)
There are now around ten mathematicians who are putting substantial effort into digesting the material — up from just three before the Oxford workshop, says Ivan Fesenko, a mathematician at the University of Nottingham, UK, who co-organized both workshops. (scientificamerican.com)