#!/usr/bin/perl

my %hash;
while(<DATA>){
  chomp;
  my @line = split /,/;
  my $first = shift @line;
  push( @{$hash{$first}}, @line );
}

foreach( sort keys %hash ){
  print "$_\t".join(' ', sort @{$hash{$_}})."\n";
}

__DATA__
text1,text-a,text-w
text2,text-b,text-y
text3,text-x,text-t
text1,text-d,text-n
text3,text-f,text-z
text3,text-e,text-w
text10,word,other 1
text10,aword,nother 1
text11,cword,tother 1
text11,zword,bother 1

__END__

prints:
text1   text-a text-d text-n text-w
text10  aword nother 1 other 1 word
text11  bother 1 cword tother 1 zword
text2   text-b text-y
text3   text-e text-f text-t text-w text-x text-z