hElLO tRaDeR,
The Theory:
http://tradingqna.com/46119/block-difference-between-block-deal-interpretation-deals
Practical:
Block deals are prearranged transactions, shares bought and sold at an agreed price and during special time slots on the exchange between the buyer and the seller.
Bulk deals are strategically placed buy orders throughout the trading day accumulating shares from the market float.
Block deals do not create spikes in price or volume during the trading day.
Bulk deals create spikes in price and volume real time as it happens.
On Block deals, the profile of the new buyer is the deciding factor for attracting medium to long term investors. If the new buyer is someone who can contribute to the growth of the company, it is considered as a positive sign.
On Bulk deals, the deciding factor is the quantity for attracting positional and short term traders.
The bulk buyers would not want the market to know about their buying activity while it happens, and is done strategically to accumulate shares as cheap as possible.
You can regularly check details of such transactions on the following link:
http://www.moneycontrol.com/stocks/marketstats/blockdeals/