It would be good if we have an option to make some portion of text with in a single log statement to bold, italic etc. Example: "User Name text box is entered as SUMANTH." for this log statement I wan...
This actually is something that is available by default. Use Log.CreateAttributes to create an attributes object to add things like bold and italics and then pass that object as the attribute parameter to your Log.Message call.
Now, it won't do PRECISELY what you want in that it will bold ALL the text and not just the one piece, but you can probably manage to make something work with multiple log messages organized into folders and nodes in your test log.
It's a cool idea to be able to selectively format portions of a message but, in the short term, you can probably use the above features to get there in the current version.