It looks like my task list has become slower as items in the list keeps on increasing (currently 1000+). Is there any way to make loading & navigation of the list faster?
The time needed to render your list is depending on the amout of data your view includes, not necessarily the total count of list elements.
You should be able to speed things up by displaying less items in your default view and maybe exclude some columns. E.g. Displaying presence information (these colorful bubbles) can be time consuming.
You can do basic before/after analysis via "Developer dashboard".