usepackage[norule,flushmargin]{footmisc}
setlength{parskip}{0pt}
usepackage{fontspec}

setmainfont[Mapping=tex-text,Ligatures={Common}, Numbers={OldStyle}]{Garamond Premier Pro} newfontfamilygreekfont[Script=Greek, Ligatures={Common}]{Garamond Premier Pro}
newfontfamilydevanagarifont[Script=Devanagari]{Sanskrit 2003}
begin{document}

begin{tabular}{ | c | c |}
hline
Q & Quota \
hline
p & g \
hline
T & l \
hline
end{tabular}

end{document}

documentclass{article}

usepackage{fontspec}
setmainfont[Ligatures   = {Common,TeX},
             Numbers     = OldStyle,
             Contextuals = Alternate
            ]{Garamond Premier Pro}

newcommandTstrut{rule{0pt}{2.6ex}}       % "top" strut
newcommandBstrut{rule[-1.3ex]{0pt}{1.3ex}} % "bottom" strut
newcommand{TBstrut}{TstrutBstrut} % top&bottom struts

begin{document}
begin{tabular}{ | c | c |}
hline
Q & Quota  \
hline
p & g  \
hline
T & l  \
hline
end{tabular}
qquad
begin{tabular}{ | c | c |}
hline
Q & Quota TBstrut \ %% top and bottom strut
hline
p & g Bstrut \  %% bottom strut only
hline
T & l Tstrut \  %% top strut only
hline
end{tabular}
end{document}