The lake is most likely named after the Japanese stringed instrument biwa, whose shape resembles the lake. The entire lake is now designated as a protected Quasi-National Park.
The JR Tokaido Main Line and the Tokaido Shinkansen lines run more or less along the southern and eastern coasts of the lake, connecting Otsu and Hikone to Kyoto and Osaka in the west and Nagoya in the east. The private Keihan Keishin Line (京阪京津線) provides the cheapest way of getting from Kyoto to Otsu and onward with a change of train to Sakamoto.
The quieter western and northern coasts are covered by the JR Kosei Line (湖西線).
Largely covered in thickets of reeds, it would be a stretch to call Lake Biwa particularly scenic, but it attracts many birds and along with them birdwatchers.
Lake Biwa's tourism industry subsists on fishing, boat rentals and a tame assortment of watersports, including even scuba diving for those who want to plumb the depths of this rather murky lake.
Bring a portable BBQ set out to Omi Maiko or Shiga Beach. Alternatively, at Omi Maiko, in summer are food vendors.
Load up a cooler full of whatever you like. There is a reasonable, tropical-themed, outdoor beach bar on the eastern end of Omi Maiko. Part of a hotel, they offer BBQ dinners at brick tables.