Don't worry - EPESI does pretty good job in keeping database small.
Let's say you have 100 contacts that belong to the same company. You paste phone number, address, city etc. into each one of them. Let's say these are values:
Phone: 123-456-7890
Address 1: 123 Some Street with long name
Address 2: Some building Suite 9999
City: City with very long name
Country (it is a select)
That's 93 characters. Times 100 it is 9300 characters. UTF-8 encodes each of the 1,112,064 code points in the Unicode character set using one to four 8-bit bytes and we use UTF-8. So even at 4 bytes (max) per character it is 37200 bytes or 36 kB.
I don't think this is a lot of waste. Compare it with the size of a simple PDF or JPG attachment.
