{{{{
{{{#!keyval
key1: value1
key2 : value2
key3: value3
This line has no key-value pairs so it doesn't turn into a table

Watch out for colons embedded deep in the line...

They might cause: unexpected results.
}}} 
}}}}

And this looks like:
----
|| key1 || value1 ||
|| key2 || value2 ||
|| key3 || value3 ||
This line has no key-value pairs so it doesn't turn into a table

Watch out for colons embedded deep in the line...

|| They might cause || unexpected results. ||
----

If you need other delimiters besides the colon, you can specify them like this:

{{{{
{{{#!keyval delim='='
key1 = value1
key2 = value2
key3 = value3
}}}
}}}}

which gets you:
----
|| key1 || value1 ||
|| key2 || value2 ||
|| key3 || value3 ||
----