A tablet would probably only substantially help you in writing code on a lightweight text editor while on the go then uploading it to an online server through FTP or whatever method you use. (Thats for Web Development).
As for college courses, you'll mostly be introduced using Java, C++ , Python or any other languages depending on your college. You cannot compile into native code (e.g for C++) using a tablets as far as I know. You should probably invest in a Laptop (for portablity) with enough RAM and processsing for a local server such as Apache(for web Developement) and VM's as suggested above and off course power conservative/long-lasting battery.