Answer in Details
It is widely recommended to avoid non-vegetarian food, alcohol, and other tamasic substances during Karthika Masam as a mark of devotion and to maintain purity in thoughts and actions. Abstaining from non-veg is believed to help devotees attain self-control, spiritual growth, and the blessings of Lord Shiva.
Therefore, if you wish to observe the traditions and honor Lord Shiva during Karthika Masam, it is best to avoid eating non-veg during this sacred month.