The only complete English translation of Plato that I know of that comes in numerous smaller volumes is the Loeb series, from Harvard University Press. It has facing-page Greek too which is the main selling point; some of the translations are rather antiquated however. Plus it would cost a lot to get all the dialogues this way. Hackett does separate paperback volumes for a lot of the dialogues, and these are pretty affordable as well.
Portable Plato
The only complete English translation of Plato that I know of that comes in numerous smaller volumes is the Loeb series, from Harvard University Press. It has facing-page Greek too which is the main selling point; some of the translations are rather antiquated however. Plus it would cost a lot to get all the dialogues this way. Hackett does separate paperback volumes for a lot of the dialogues, and these are pretty affordable as well.