Perl can resolve your problem with one line:

perl -ne 'if(/(\w+\.csv)/){close $fh if defined $fh;open $fh,">$1"} el
+sif(/([0-9.-]+)/){print $fh "$1\n"}' file.txt
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or few more:

open FILE, "<file.txt";           # Open the file
while( <FILE> ) {                 # read a line
    if ( /(\w+\.csv)/ ) {         # If the line is a filename...
        close $fh if defined $fh; # close previous
        open $fh,">$1";           # and open new for writing
    } elsif ( /([0-9.-]+)/ ) {    # If the line is a number...
        print $fh "$1\n";         # write it
    }
}
close $fh;                        # close the files opened
close FILE;
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