Copy, Paste, Moving and Aligning Tables

I canot seem to find a reliable method to copy, paste align tables.

Example
If I create a smal table 5 columns x 5 rows width and height 0.5cm
I want to place 4 in a row and I want 5 rows, all tables equally aligned
horizontally and vertically.

Question 1
What is the simplest method to achieve this?

My Observations
1. I find if I copy and paste....the second table does not align to the first.
2. Copy and Paste seems unreliable.....by using the top left corner, drag
and drop does not seem to work every time, why might this be the case?

Any advise would be appreciated

Thanks in advance