I have several different processes within a single project that I work on. I am constantly opening and closing tabs(java files) in the code editor for that particular process.
I've edited this answer as per below comment (include essential parts of answer in this post).
Yes, you can save off groups of tabs in Eclipse by installing this Session Manager plug-in.
I've wanted this functionality in Eclipse as well. I recently wrote a feature and have been successfully using it for a few months now. It is a new OSGi type extension and works with Eclipse Neon and above.
Here's how to install it.
Full set of instructions are here: http://chrishull.com/projects/eclipse/
Please give it a try and send comments. I've found it a very useful tool as I work with several Eclipse projects at once and need to recall file groups.
Hope you enjoy it;
-Chris