Is AppendTo a good approach to making a list of lists?

Questions
1

I have lists such as

{{1, 1}, {8, 2}, {7, 4}, {1, 1}}

then

{{8, 2}, {15, 5}, {7, 4}, {8, 2}}

then

{{18, 4}, {15, 5}, {8, 2}, {18, 4}}

I want to create

{{{1, 1}, {8, 2}, {7, 4}, {1, 1}} , {{8, 2}, {15, 5}, {7, 4}, {8, 2}} , {{18, 4}, {15, 5}, {8, 2}, {18, 4}}}

I have tried AppendTo first list , second list, then AppendTo result to third list, but get

{{1, 1}, {8, 2}, {7, 4}, {1, 1}, {{8, 2}, {15, 5}, {7, 4}, {8, 2}}, {{18, 4}, {15, 5}, {8, 2}, {18, 4}}}

which is the wrong nesting. Any ideas?

2

You can just nest them in the top list:

In[1]:= lst1 = {{1, 1}, {8, 2}, {7, 4}, {1, 1}};
lst2 = {{8, 2}, {15, 5}, {7, 4}, {8, 2}};
lst3 = {{18, 4}, {15, 5}, {8, 2}, {18, 4}};
{lst1, lst2, lst3}

Out[4]= {{{1, 1}, {8, 2}, {7, 4}, {1, 1}}, {{8, 2}, {15, 5}, {7, 
   4}, {8, 2}}, {{18, 4}, {15, 5}, {8, 2}, {18, 4}}}

Best,

David