how to allocate ram to c# process

C# is a managed programming language which means that you do not have to work around with memory yourself. The good thing is that .NET's VM does that for you, the bad thing is that you cannot manage the memory like you can in C++ or C. 

 

You mentioned that you want to increase the memory consumption (size) for that program. I am here to tell you that even increasing the memory block size won't help you with this. The problem is with the processing time that is required. Bigger file would take more CPU cycles and that is what takes time. Even if you increase the RAM space for this, your CPU won't do anything better however you will successfully add an overhead CPU cycle just to manage the "extra" memory. 

 

So, try to cut short the file into chunks and then manage it an create the Excel files. Otherwise, if none of these is possible then try to: