What makes your Ram truck 318 tap at start up then run smooth after a few seconds even after oil change?

after the newer vehicles sit a little bit the oil drains back down instead of sitting in the motor the tap u here is your lifters it is hurting nothing so don't worry about it.

Try installing a K&N or Napa Gold oil filter, these have an anti drainback valve in the filter. This helped on my 99' 360.