Easy, 5 минут 
const
n=5;
m=5;
var
i,j:integer;
a:array[1..n,1..m] of integer;
begin
randomize;
for i:=1 to n do
 begin
    for j:=1 to n do
begin
a[i,j]:=random(99)+1;
end;
writeln;
end;

for i:=1 to n do
  for j:=1 to n do
begin
if (i=j) or (i<j) then a[i,j]:=0;
end;

for i:=1 to n do
begin
for j:=1 to n do write(a[i,j]:3);
writeln;
end;



end.