Merge combines several files together into one file.  Click Select Folder to select the folder and click on the files you want to be in the merge then click on the ==> button to place them in the Files to Merge box.  Use the <== button to remove them from the Files to Merge box.  Once you have selected all the files you want to merge together and the PassPhrase has been defined, select the filename you want these files merged to then click on Merge.  Because this has the potential of being a rather large file, expect the encryption process to take a moment or two.

This is far easier than the merge encryption.  All you have to do is define the PassPhrase, select the merged filename and define in which folder the files will be extracted to.  After the file is decrypted, the contained files will be extracted to the folder you specified.  Note that matching files will be overwritten when they are extracted.