new worksheet, fill with row number

add one more column, fill with random text aa bb cc

select column B and plot column plot

open PD, go to panel tab, set panel by column C, ok

open graph publisher app, go to line thickness, select axis line checkbox to set line thickness to 1, apply

open axis dialog with top axis, go to line and tick tab,

change thickness for Line to 3, ok
==> frame of top table it still thin (bottom line is thick since there is Y=0 affect by top axis line)