Surface tension is the property of the surface of a liquid which allows it to resist an external force. It is due to the cohesive nature (stickiness and clumpability) of the water molecules. Since water has a strong surface tension:
1) The surface tension of water provides the necessary wall tension for the formation of bubbles with water
2) It is responsible for the shape of liquid droplets, too
3) Small objects will "float" on the surface of a fluid, as long as the object cannot break through and separate the top layer of water molecules
If surface tension is weak, the reverse happens. Bubbles will come from round to spherical, small objects will not float, water will fall as it is, without forming spherical droplets and will not immediately spread.