t = table;
for i = 1:3
column1 = rand(2,1);
column2 = rand(2,1);
tempt = table(column1, column2, 'VariableNames',{'c1','c2'});
t = [t;tempt];
end
If you know the length of the final t, consider preallocating t in line 1 using zeros or ones to improve performance.