Hmm. That is a difficult request, I doubt any one lakorn can fulfill it.
Pitsawat (2016) - has a good take on the myths and beliefs of Thailand, such as karma though it is a fictional tale.
https://mydramalist.com/23472-bpoop-phaeh-saniwaat - is a very popular drama that gives a peek into ancient history and does have some events based on actual history, as well as having a charming love story.
As for a good Thai modern drama, Thailand's lakorns are not slice of life and are often very dramatic stories that I doubt have much to do with actual Thailand peoples' ways of life. Most of the English subbed lakorns I've watched at least, are like that. To find a good representation of Thailand modern culture, it would be better to turn to documentaries rather than dramas or lakorns I believe.