Some people do it to avoid clashes with reserved words. Example: in some DBMSs, you cannot name your table 'user' because it is a reserved word. "user" (doubl

Some people do it to avoid clashes with reserved words. Example: in some DBMSs, you cannot name your table 'user' because it is a reserved word. "user" (double quotes) works, but there may be gotchas as sometimes double quotes suddenly make identifiers case-sensitive... but only if the filesystem is case-sensitive... things like that. So you can either deal with the gotchas or say fuck it, put a prefix "tbl" and call it a day.