Cable was born in Calcutta. He was the son of George Hebberd Cable, a superintendent with the Indian Customs and Excise Service, and Emily Maria Pickersgill. He was educated privately and at the University of Calcutta, and then joined Bird & Co, a merchant house in Calcutta which had interests in many different areas of commerce, especially labour contracting (in which it had started), coal and jute. In 1886 he became a partner in the company. By 1896 the company directly employed 15,000 people and contracted 15,000 more. Much of this expansion was due to Cable's business acumen and his knowledge of India and good relations with its people. He also set up a subsidiary in the City of London to ease British investments in the company. By 1914 he was senior partner of Bird & Co.
In 1917 Bird acquired a controlling interest in F. W. Heilgers & Co, another Calcutta merchant house, creating by far the largest company in India, employing 100,000 people.
From 1903 to 1905, Cable was member of the Viceroy's Council and in 1905–1906 he was Sheriff of Calcutta; he was knighted in 1906 when the Prince and Princess of Wales visited the city. He was also High Sheriff of Devon in 1916. He was ennobled, as Baron Cable, of Ideford in the County of Devon, in the 1921 New Year Honours.
On 10 October 1888, he married Lilian Sarah Sparkes, daughter of Weston Joseph Sparkes. They had two daughters and one son, who was killed fighting in the First World War in 1915, so that the barony became extinct on Cable's death.