Without knowing all of the specifics about your catalog and seeing debug data myself it would be very very difficult to give you specific advice. Your issue may likely be too broad for us to diagnose via Magento.SE. A few thoughts, though, to get you on the right path:

• Bundles are comprised of other products, and specifically their pricing and weight can be a function of their selections' prices and weights. If all of your simple products are also found in bundles it may be conceivable that, if all bundles are requested, then all simples are also requested.
• If you have any customization in the Catalog > Products view at all this may lead to unforeseen consequences. (For example, I've seen a certain product matrix plugin that loaded all attributes including gallery attributes, for all product types even if they weren't being used in the grid).
• When viewing a subset of your bundles (in the grid view for instance) you have the ability by default to view 20, 50, 100, 200 at a time; this pagination should prevent an excessive amount of data from being loaded. If there is evidence still that all products are being loaded even when only 20 are being displayed I would begin debugging by methodically disabling your local modules one-at-a-time until the issue subsides. Likely there's a local module that is doing a $product->getCollection()->load() which is fetching all products in that view.

For specific debugging advice (disabling local modules, for instance) see the following answer which gives step-by-step advice on how to proceed systematically when diagnosing these types of issues:

http://magento.stackexchange.com/a/429/336

Without knowing all of the specifics about your catalog and seeing debug data myself it would be very very difficult to give you specific advice. Your issue may likely be too broad for us to diagnose via Magento.SE. A few thoughts, though, to get you on the right path:

• Bundles are comprised of other products, and specifically their pricing and weight can be a function of their selections' prices and weights. If all of your simple products are also found in bundles it may be conceivable that, if all bundles are requested, then all simples are also requested.
• If you have any customization in the Catalog > Products view at all this may lead to unforeseen consequences. (For example, I've seen a certain product matrix plugin that loaded all attributes including gallery attributes, for all product types even if they weren't being used in the grid).
• When viewing a subset of your bundles (in the grid view for instance) you have the ability by default to view 20, 50, 100, 200 at a time; this pagination should prevent an excessive amount of data from being loaded. If there is evidence still that all products are being loaded even when only 20 are being displayed I would begin debugging by methodically disabling your local modules one-at-a-time until the issue subsides. Likely there's a local module that is doing a $product->getCollection()->load() which is fetching all products in that view.

For specific debugging advice (disabling local modules, for instance) see the following answer which gives step-by-step advice on how to proceed systematically when diagnosing these types of issues:

https://magento.stackexchange.com/a/429/336