for my $table (in $tables) { 
my $rownum=1; 
while($rownum<=$table->Rows->Count){
print "calling cell1\n";  
my $cell1=$table->Cell($rownum,1);
print "cell1-$cell1 calling text\n";
# prints cell1-Win32::OLE=HASH(0x1c7fbc32b50) calling text
my $text1=$cell1->ConvertToText(wdSeparateByTabs)->Text;
#This is where it fails with the message
#Win32::OLE(0.1713) error 0x80020011: "Does not support a collection"
 #   in METHOD/PROPERTYGET "" 
print "after text1cell1  = $text1\n"; 
                          $rownum++;}
                                       }
[download]

You can't make up function calls and expect them to work. Where in the (already linked) Microsoft Documentation did you find that the ->ConvertToText method exists on the Cell object?

Following the approach I outlined above with the interactive testing window of Microsoft Word, I used the following snippet to get at the text content of an arbitrary cell:

set T = activeDocument.Tables.Item(1)
print T.Cell(2,2).Range.Text
[download]

Translating this to Perl would be something like this:

print $table->Cell(2,2)->Range->Text
[download]