Books like Epistulae Morales Ad Lucilium
Seneca the Younger
Epistulae Morales Ad Lucilium is 337 pages, about 6 hours 11 minutes at 250 words a minute.
12 books to read next
How long each takes
Meditations 3.7 h 
Manual 48 min The Dialogues of Plato / The Seventh Letter 14.9 h 
Plutarch's Moralia 5.3 h 
Lives 8.6 h 
De Officiis 4.7 h 
Gorgias 3.7 h 
A Manual for Living 1.6 h 
Protagoras 2.7 h 
The Discourses of Epictetus 8.3 h 
Self-knowledge 3.8 h 
Cato Maior de Senectute 3.4 h Bar height shows length. Estimated at 250 words a minute.