Get rid of \addlinespace in kable
Solution 1:
You can add the argument linesep = "" to kable. This will be passed on to kable_latex where it overwrites the default
linesep = if (booktabs) c('', '', '', '', '\\addlinespace') else '\\hline'
Example:
kable(cars, format = "latex", booktabs = TRUE, linesep = "")