documentclass{article}
usepackage{hhline}
usepackage{caption}
usepackage{booktabs}
begin{document}
begin{table}[htb]
centering
sffamily
captionsetup{font={bf,sf}}
caption*{Access Levels}
begin{tabular}{||*{5}{l||}}
hhline{|t:=:t:=:t:=:t:=:t:=:t|}
 bfseries Modifier              & bfseries Class & bfseries Package & bfseries Subclass & bfseries World \
hhline{|:=::=::=::=::=:|}
texttt{public}                  & Y               & Y                 & Y                  & Y               \
hhline{|:=::=::=::=::=:|}
texttt{protected}               & Y               & Y                 & Y                  & N               \
hhline{|:=::=::=::=::=:|}
itshape no modifier             & Y               & Y                 & N                  & N               \
hhline{|:=::=::=::=::=:|}
texttt{private}                 & Y               & N                 & N                  & N               \
hhline{|b:=:b:=:b:=:b:=:b:=:b|}
end{tabular}
end{table}

begin{table}[htb]
centering
sffamily
captionsetup{font={bf,sf}}
caption*{Access Levels}
begin{tabular}{l*{4}{c}}
toprule
 bfseries Modifier  & bfseries Class & bfseries Package & bfseries Subclass & bfseries World \
midrule
texttt{public}      & Y               & Y                 & Y                  & Y               \
texttt{protected}   & Y               & Y                 & Y                  & N               \
itshape no modifier & Y               & Y                 & N                  & N               \
texttt{private}     & Y               & N                 & N                  & N               \ bottomrule
end{tabular}
end{table}
end{document}