Your style declaration is incorrect. You're missing a unit on the border width. You also need to specify the border style, and optionally the border colour as well.
Try using the correct CSS syntax for the border:
<table style="border:1px solid black;">
CSS border property | W3Schools[
^]
Or just setting the older "border" attribute:
<table border="1">
HTML table tag | W3Schools[
^]