You can use an Arraylist to store the strings
ArrayList<String> list = new ArrayList<String>();
Then on every button click add the text to to the arraylist  like
public void onClick(View v) {
String clickedText;
switch(v.getId())
{
   case R.id.your_1st_button_id:
   clickedText=your_textView.getText().toString();
   break;
   case R.id.your_2nd_button_id:
   clickedText=your_1st_textView.getText().toString();
   break;
   case R.id.your_3rd_button_id:
   clickedText=your_3rd_textView.getText().toString();
   break;
 }
  list.add(clickedText);
}
After that send the arraylist as extra with Intent using 
 Intent i=new Intent(this,Second.class);
 i.putStringArrayListExtra("list", ar);
 startActivity(i);
Now in the second activity get the arraylist like 
ArrayList<String> ar1=getIntent().getExtras().getStringArrayList("list");
Now from second activity you can access all arraylist data with a for loop
 for (String s : ar1){
  Log.d("My array list content: ", s);
 }