You may proceed like shown below.
nodes = readtable('https://in.mathworks.com/matlabcentral/answers/uploaded_files/1068640/aaa_ele.txt','HeaderLines',1) ; % read the nodal data
vert = readtable('https://in.mathworks.com/matlabcentral/answers/uploaded_files/1068645/aaa_node.txt','HeaderLines',1); % read the vertices data
% Remove the last lines
nodes(end,:) =[] ; % last line has some text, remove it
vert(end,:) = [] ; % last lines has some text, remove it ;
t = table2array(nodes(:,2:4)) ; % nodal connectivity data
p = table2array(vert(:,2:3)) ; % coordinates/ vertices
triplot(t,p(:,1),p(:,2)) ; % plot the mesh
