Step 1: Select the rows in the the source table

Select the first cell of the first row

And the with shift or control keys the other rows

Step 2: Copy it in using the keyboard

For example in windows hit ctrl-c

Step 3: Paste it in another table (with identical structure!)

Select the first cell in row where to insert it

And press the keyboard short cut to paste (e.g. ctrl-v in windows)