The expectation is that a table copied from the PDF will preserve the order of rows/columns/text. For example, on page 68 of a Progamming Ruby book, there's a table listing regular expression characters. The Acrobat results below represent what I would expect from evince as well.

Operation: I am selecting the table region with mouse selection/highlight and pasting into another text document. 

OS: Ubuntu 11.04

Evince 2.32.0 results:
\d
\D
\s
\S
\w
\W
As [ . . . ] Meaning
[0-9] Digit character
[^0-9] Any character except a digit
[\s\t\r\n\f] Whitespace character
[^\s\t\r\n\f] Any character except whitespace
[A-Za-z0-9_] Word character
[^A-Za-z0-9_] Any character except a word character
POSIX Character Classes
[:alnum:]
[:alpha:]
[:blank:]
[:cntrl:]
[:digit:]
[:graph:]
[:lower:]
[:print:]
[:punct:]
[:space:]
[:upper:]
[:xdigit:]
Alphanumeric
Uppercase or lowercase letter
Blank and tab
Control characters (at least 0x00–0x1f, 0x7f)
Digit
Printable character excluding space
Lowercase letter
Any printable character (including space)
Printable character excluding space and alphanumeric
Whitespace (same as \s)
Uppercase letter
Hex digit (0–9, a–f, A–F)

Acrobat Reader 9 results:
\d [0-9] Digit character
\D [^0-9] Any character except a digit
\s [\s\t\r\n\f] Whitespace character
\S [^\s\t\r\n\f] Any character except whitespace
\w [A-Za-z0-9_] Word character
\W [^A-Za-z0-9_] Any character except a word character
POSIX Character Classes
[:alnum:] Alphanumeric
[:alpha:] Uppercase or lowercase letter
[:blank:] Blank and tab
[:cntrl:] Control characters (at least 0x00–0x1f, 0x7f)
[:digit:] Digit
[:graph:] Printable character excluding space
[:lower:] Lowercase letter
[:print:] Any printable character (including space)
[:punct:] Printable character excluding space and alphanumeric
[:space:] Whitespace (same as \s)
[:upper:] Uppercase letter
[:xdigit:] Hex digit (0–9, a–f, A–F)