I was facing a similar issue, except that I needed to remove multiple files, not just one file, and also we are on Subversion 1.6 which doesn't support the --patern directive.
-- backup current SVN
$ cp -R /svn /svnSAVE
-- dump repository
$ svnadmin dump /svn/root > svnDump
-- create new dump while excluding the very large file
$ svndumpfilter exclude "/path/file.csv" < svnDump > newSvnDump0
-- {note: should see a message like this}:
-- Dropped 1 node:
-- '/path/file.csv'
-- create another new dump while excluding another very large file
$ svndumpfilter exclude "/path/anotherFile.csv" < newSvnDump0 > newSvnDump1
-- remove the old svn
$ rm -rf /svn
-- recreate the svn directories
$ mkdir -p /svn/root
-- recreate the SVN
$ svnadmin create /svn/root
-- repopulate the fresh repository with the dump
$ cat newSvnDump1 | svnadmin load /svn/root
-- update the conf files from the saved copy into the new copy...
$ cp /svnSAVE/root/conf/* /svn/root/conf
Now the repository should not contain the 2 large files "file.csv" and "anotherFile.csv"